diff --git a/extern/libpng/include/scripts/list b/extern/libpng/include/scripts/list
deleted file mode 100644
index 7cec1e3372..0000000000
--- a/extern/libpng/include/scripts/list
+++ /dev/null
@@ -1,23 +0,0 @@
-vers.dfn
-symbols.dfn
-sym.dfn
-pnglibconf.h.prebuilt
-pnglibconf.dfa
-options.awk
-makefile.netbsd
-makefile.solaris-x86
-makefile.solaris
-makefile.so9
-makefile.sgi
-makefile.sggcc
-makefile.openbsd
-makefile.sco
-makefile.linux
-makefile.hpux
-makefile.hpgcc
-makefile.elf
-makefile.dec
-makefile.beos
-makefile.64sunu
-makefile.32sunu
-def.dfn
diff --git a/extern/libpng/include/scripts/makefile.watcom b/extern/libpng/include/scripts/makefile.watcom
deleted file mode 100644
index 97a77bbf9d..0000000000
--- a/extern/libpng/include/scripts/makefile.watcom
+++ /dev/null
@@ -1,122 +0,0 @@
-# Makefile for libpng
-# Watcom C/C++ 10.0 and later, 32-bit protected mode, flat memory model
-
-# Copyright (C) 2000, Pawel Mrochen, based on makefile.msc which is
-# copyright 1995 Guy Eric Schalnat, Group 42, Inc.
-#
-# This code is released under the libpng license.
-# For conditions of distribution and use, see the disclaimer
-# and license in png.h
-
-# To use, do "wmake /f scripts\makefile.watcom"
-
-
-# ---------------------- Watcom C/C++ 10.0 and later -----------------------
-
-# Where the zlib library and include files are located
-ZLIBLIB=..\zlib
-ZLIBINC=..\zlib
-
-# Target OS
-OS=DOS
-#OS=NT
-
-# Target CPU
-CPU=6		# Pentium Pro
-#CPU=5		# Pentium
-
-# Calling convention
-CALLING=r	# registers
-#CALLING=s	# stack
-
-# Uncomment next to put error messages in a file
-#ERRFILE=>>pngerrs
-
-# --------------------------------------------------------------------------
-
-
-CC=wcc386
-CFLAGS=-$(CPU)$(CALLING) -fp$(CPU) -fpi87 -oneatx -mf -bt=$(OS) -i=$(ZLIBINC) -zq
-LD=wcl386
-LDFLAGS=-zq
-
-O=.obj
-
-OBJS1=png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
-OBJS2=pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
-OBJS3=pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
-
-
-all: test
-
-# see scripts/pnglibconf.mak for more options
-# to support watcom calling conventions it is necessary to set PNG_API_RULE to 2
-# in pnglibconf.h - copy scripts/pnglibconf.h.prebuilt, delete the first line and change
-# the definition of PNG_API_RULE from 0 to 2.
-#
-# If you know how to do this with the Watcom build system please supply a patch
-# for this makefile to the PNG implementation list.
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	@echo please copy scripts/pnglibconf.h.prebuilt and change PNG_API_RULE to 2
-
-png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngset$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngget$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngmem$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngrio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngtest$(O): png.h pngconf.h pnglibconf.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
-	wlib -b -c -n -q libpng.lib $(OBJS1)
-	wlib -b -c -q libpng.lib $(OBJS2)
-	wlib -b -c -q libpng.lib $(OBJS3)
-
-pngtest.exe: pngtest.obj libpng.lib
-	$(LD) $(LDFLAGS) pngtest.obj libpng.lib $(ZLIBLIB)\zlib.lib
-
-test: pngtest.exe .symbolic
-	pngtest.exe
-
-
-# End of makefile for libpng
diff --git a/extern/libpng/include/scripts/pnglibconf.h b/extern/libpng/include/scripts/pnglibconf.h
deleted file mode 100644
index b1d2169105..0000000000
--- a/extern/libpng/include/scripts/pnglibconf.h
+++ /dev/null
@@ -1,176 +0,0 @@
-
-/* libpng STANDARD API DEFINITION */
-
-/* pnglibconf.h - library build configuration */
-
-/* libpng version 1.5.0 - last changed on January 6, 2011 */
-
-/* Copyright (c) 1998-2011 Glenn Randers-Pehrson */
-
-/* This code is released under the libpng license. */
-/* For conditions of distribution and use, see the disclaimer */
-/* and license in png.h */
-
-/* pnglibconf.h */
-/* Machine generated file: DO NOT EDIT */
-/* Derived from: scripts/pnglibconf.dfa */
-#ifndef PNGLCONF_H
-#define PNGLCONF_H
-/* settings */
-#define PNG_MAX_GAMMA_8 11
-#define PNG_CALLOC_SUPPORTED
-#define PNG_QUANTIZE_RED_BITS 5
-#define PNG_USER_WIDTH_MAX 1000000L
-#define PNG_QUANTIZE_GREEN_BITS 5
-#define PNG_API_RULE 0
-#define PNG_QUANTIZE_BLUE_BITS 5
-#define PNG_USER_CHUNK_CACHE_MAX 0
-#define PNG_USER_HEIGHT_MAX 1000000L
-#define PNG_sCAL_PRECISION 5
-#define PNG_COST_SHIFT 3
-#define PNG_WEIGHT_SHIFT 8
-#define PNG_USER_CHUNK_MALLOC_MAX 0
-#define PNG_DEFAULT_READ_MACROS 1
-#define PNG_ZBUF_SIZE 8192
-#define PNG_GAMMA_THRESHOLD_FIXED 5000
-/* end of settings */
-/* options */
-#define PNG_INFO_IMAGE_SUPPORTED
-#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-#define PNG_POINTER_INDEXING_SUPPORTED
-#define PNG_WARNINGS_SUPPORTED
-#define PNG_FLOATING_ARITHMETIC_SUPPORTED
-#define PNG_WRITE_SUPPORTED
-#define PNG_WRITE_INTERLACING_SUPPORTED
-#define PNG_WRITE_16BIT_SUPPORTED
-#define PNG_EASY_ACCESS_SUPPORTED
-#define PNG_ALIGN_MEMORY_SUPPORTED
-#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-#define PNG_USER_LIMITS_SUPPORTED
-#define PNG_FIXED_POINT_SUPPORTED
-/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
-#define PNG_ERROR_TEXT_SUPPORTED
-#define PNG_READ_SUPPORTED
-/*#undef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED*/
-#define PNG_BENIGN_ERRORS_SUPPORTED
-#define PNG_SETJMP_SUPPORTED
-#define PNG_WRITE_FLUSH_SUPPORTED
-#define PNG_MNG_FEATURES_SUPPORTED
-#define PNG_FLOATING_POINT_SUPPORTED
-#define PNG_INCH_CONVERSIONS_SUPPORTED
-#define PNG_STDIO_SUPPORTED
-#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-#define PNG_USER_MEM_SUPPORTED
-#define PNG_IO_STATE_SUPPORTED
-#define PNG_SET_USER_LIMITS_SUPPORTED
-#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
-#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
-#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
-#define PNG_WRITE_FILTER_SUPPORTED
-#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
-#define PNG_WRITE_iCCP_SUPPORTED
-#define PNG_READ_TRANSFORMS_SUPPORTED
-#define PNG_READ_GAMMA_SUPPORTED
-#define PNG_READ_bKGD_SUPPORTED
-#define PNG_UNKNOWN_CHUNKS_SUPPORTED
-#define PNG_READ_sCAL_SUPPORTED
-#define PNG_WRITE_hIST_SUPPORTED
-#define PNG_READ_OPT_PLTE_SUPPORTED
-#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
-#define PNG_WRITE_gAMA_SUPPORTED
-#define PNG_READ_GRAY_TO_RGB_SUPPORTED
-#define PNG_WRITE_pCAL_SUPPORTED
-#define PNG_READ_INVERT_ALPHA_SUPPORTED
-#define PNG_WRITE_TRANSFORMS_SUPPORTED
-#define PNG_READ_sBIT_SUPPORTED
-#define PNG_READ_PACK_SUPPORTED
-#define PNG_WRITE_SWAP_SUPPORTED
-#define PNG_READ_cHRM_SUPPORTED
-#define PNG_WRITE_tIME_SUPPORTED
-#define PNG_READ_INTERLACING_SUPPORTED
-#define PNG_READ_tRNS_SUPPORTED
-#define PNG_WRITE_pHYs_SUPPORTED
-#define PNG_WRITE_INVERT_SUPPORTED
-#define PNG_READ_RGB_TO_GRAY_SUPPORTED
-#define PNG_WRITE_sRGB_SUPPORTED
-#define PNG_READ_oFFs_SUPPORTED
-#define PNG_WRITE_FILLER_SUPPORTED
-#define PNG_WRITE_TEXT_SUPPORTED
-#define PNG_WRITE_SHIFT_SUPPORTED
-#define PNG_PROGRESSIVE_READ_SUPPORTED
-#define PNG_READ_SHIFT_SUPPORTED
-#define PNG_CONVERT_tIME_SUPPORTED
-#define PNG_READ_USER_TRANSFORM_SUPPORTED
-#define PNG_READ_INT_FUNCTIONS_SUPPORTED
-#define PNG_READ_USER_CHUNKS_SUPPORTED
-#define PNG_READ_hIST_SUPPORTED
-#define PNG_READ_16BIT_SUPPORTED
-#define PNG_READ_SWAP_ALPHA_SUPPORTED
-#define PNG_READ_COMPOSITE_NODIV_SUPPORTED
-#define PNG_SEQUENTIAL_READ_SUPPORTED
-#define PNG_READ_BACKGROUND_SUPPORTED
-#define PNG_READ_QUANTIZE_SUPPORTED
-#define PNG_READ_iCCP_SUPPORTED
-#define PNG_READ_STRIP_ALPHA_SUPPORTED
-#define PNG_READ_PACKSWAP_SUPPORTED
-#define PNG_READ_sRGB_SUPPORTED
-#define PNG_WRITE_tEXt_SUPPORTED
-#define PNG_READ_gAMA_SUPPORTED
-#define PNG_READ_pCAL_SUPPORTED
-#define PNG_READ_EXPAND_SUPPORTED
-#define PNG_WRITE_sPLT_SUPPORTED
-#define PNG_READ_SWAP_SUPPORTED
-#define PNG_READ_tIME_SUPPORTED
-#define PNG_READ_pHYs_SUPPORTED
-#define PNG_WRITE_SWAP_ALPHA_SUPPORTED
-#define PNG_TIME_RFC1123_SUPPORTED
-#define PNG_READ_TEXT_SUPPORTED
-#define PNG_WRITE_BGR_SUPPORTED
-#define PNG_USER_CHUNKS_SUPPORTED
-#define PNG_CONSOLE_IO_SUPPORTED
-#define PNG_WRITE_PACK_SUPPORTED
-#define PNG_READ_FILLER_SUPPORTED
-#define PNG_WRITE_bKGD_SUPPORTED
-#define PNG_WRITE_tRNS_SUPPORTED
-#define PNG_READ_sPLT_SUPPORTED
-#define PNG_WRITE_sCAL_SUPPORTED
-#define PNG_WRITE_oFFs_SUPPORTED
-#define PNG_READ_tEXt_SUPPORTED
-#define PNG_WRITE_sBIT_SUPPORTED
-#define PNG_READ_INVERT_SUPPORTED
-#define PNG_READ_16_TO_8_SUPPORTED
-#define PNG_WRITE_cHRM_SUPPORTED
-#define PNG_16BIT_SUPPORTED
-#define PNG_WRITE_USER_TRANSFORM_SUPPORTED
-#define PNG_READ_BGR_SUPPORTED
-#define PNG_WRITE_PACKSWAP_SUPPORTED
-#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
-#define PNG_sCAL_SUPPORTED
-#define PNG_WRITE_zTXt_SUPPORTED
-#define PNG_sBIT_SUPPORTED
-#define PNG_cHRM_SUPPORTED
-#define PNG_bKGD_SUPPORTED
-#define PNG_tRNS_SUPPORTED
-#define PNG_WRITE_iTXt_SUPPORTED
-#define PNG_oFFs_SUPPORTED
-#define PNG_USER_TRANSFORM_PTR_SUPPORTED
-#define PNG_USER_TRANSFORM_INFO_SUPPORTED
-#define PNG_hIST_SUPPORTED
-#define PNG_iCCP_SUPPORTED
-#define PNG_sRGB_SUPPORTED
-#define PNG_READ_zTXt_SUPPORTED
-#define PNG_gAMA_SUPPORTED
-#define PNG_pCAL_SUPPORTED
-#define PNG_CHECK_cHRM_SUPPORTED
-#define PNG_tIME_SUPPORTED
-#define PNG_pHYs_SUPPORTED
-#define PNG_READ_iTXt_SUPPORTED
-#define PNG_TEXT_SUPPORTED
-#define PNG_SAVE_INT_32_SUPPORTED
-#define PNG_sPLT_SUPPORTED
-#define PNG_tEXt_SUPPORTED
-#define PNG_zTXt_SUPPORTED
-#define PNG_iTXt_SUPPORTED
-/* end of options */
-#endif /* PNGLCONF_H */