Clean up math functions

- Remove checking for standard functions from the build system
- Prefix all invocations with std::
- Replace suffixed functions with unprefixed versions
- Include <cmath> in all files that use it and remove the global include

e.g. floorf(x) -> std::floor(x)

src/archutils/Win32/DialogUtil.cpp

@@ -4,6 +4,8 @@
 #include "ThemeManager.h"
 #include "archutils/Win32/ErrorStrings.h"
 
+#include <cmath>
+
 // Create*Font copied from MFC's CFont
 
 // pLogFont->nHeight is interpreted as PointSize * 10
@@ -20,7 +22,7 @@ static HFONT CreatePointFontIndirect(const LOGFONT* lpLogFont)
 	::DPtoLP(hDC, &pt, 1);
 	POINT ptOrg = { 0, 0 };
 	::DPtoLP(hDC, &ptOrg, 1);
-	logFont.lfHeight = -abs(pt.y - ptOrg.y);
+	logFont.lfHeight = -std::abs(pt.y - ptOrg.y);
 
 	ReleaseDC(nullptr, hDC);
 
@@ -84,7 +86,7 @@ void DialogUtil::LocalizeDialogAndContents( HWND hdlg )
 /*
  * (c) 2002-2004 Chris Danford
  * All rights reserved.
- * 
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
@@ -94,7 +96,7 @@ void DialogUtil::LocalizeDialogAndContents( HWND hdlg )
  * copyright notice(s) and this permission notice appear in all copies of
  * the Software and that both the above copyright notice(s) and this
  * permission notice appear in supporting documentation.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF