Added RageSoundDriver_SDL to the build

stepmania/src/Makefile.am

@@ -16,9 +16,24 @@ AM_CFLAGS   += -O2
 
 # This is a little hacky; we use our own version of SDL and SDL_sound, and I don't
 # want to have to integrate their entire build systems.
+# <roothorick> Why --disable-alsa --disable-oss? Because SDL and our own
+#              sound system conflict, which might be safe on OSS (SDL simply
+#              gets rejected), but on ALSA, even when going through the OSS
+#              emu, this conflict causes StepMania to hang on soundcards
+#              incapable of handling multiple applications at the same time
+#              (which is basically everything besides SB Lives). This hang
+#              happens because if you try to open() a character device
+#              corresponding to an ALSA soundcard that's being used and
+#              can't handle multiple applications at one time, the open()
+#              call doesn't return until whatever's using the card closes it
+#              (in this case, StepMania, which is waiting for SDL to bring
+#              itself up, which will never happen, because the open() is
+#              hanging, because... you get the idea.) Setting these switches
+#              keep SDL from trying to grab the soundcard, so we have it all
+#              to ourselves, thus preventing that nasty hang on boot.
 SDL-1.2.5/src/.libs/libSDL.a:
 	cd SDL-1.2.5 && ./configure \
-		--disable-nasm --disable-arts --disable-esd --enable-static --disable-shared --enable-debug
+		--disable-nasm --disable-arts --disable-esd --enable-static --disable-shared --enable-debug --disable-alsa --disable-oss 
 	make -C SDL-1.2.5
 
 SDL_sound-1.0.0/.libs/libSDL_sound.a:
@@ -145,6 +160,10 @@ Sound_ALSA9 = \
 	arch/Sound/RageSoundDriver_ALSA9.cpp \
 	arch/Sound/RageSoundDriver_ALSA9.h
 
+Sound_SDL = \
+        arch/Sound/RageSoundDriver_SDL.cpp \
+	arch/Sound/RageSoundDriver_SDL.h
+
 Sound_Null = \
 	arch/Sound/RageSoundDriver_Null.cpp \
 	arch/Sound/RageSoundDriver_Null.h
@@ -156,6 +175,7 @@ endif
 if HAVE_OSS
 Sound += $(Sound_OSS)
 endif
+Sound += $(Sound_SDL)
 
 stepmania_SOURCES = $(Rage) $(DataStructures) $(FileTypes) $(StepMania) $(Transitions) \
 		    $(Actors) $(ActorsInMenus) $(ActorsInGameplay) $(Screens) $(GlobalSingletons) \