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/LuaManager.cpp

@@ -16,6 +16,7 @@
 #include <sstream> // conversion for lua functions.
 #include <csetjmp>
 #include <cassert>
+#include <cmath>
 #include <map>
 
 LuaManager *LUA = nullptr;
@@ -170,9 +171,9 @@ static int GetLuaStack( lua_State *L )
 {
 	RString sErr;
 	LuaHelpers::Pop( L, sErr );
-	
+
 	lua_Debug ar;
-	
+
 	for( int iLevel = 0; lua_getstack(L, iLevel, &ar); ++iLevel )
 	{
 		if( !lua_getinfo(L, "nSluf", &ar) )
@@ -181,7 +182,7 @@ static int GetLuaStack( lua_State *L )
 		const char *file = ar.source[0] == '@' ? ar.source + 1 : ar.short_src;
 		const char *name;
 		std::vector<RString> vArgs;
-		
+
 		if( !strcmp(ar.what, "C") )
 		{
 			for( int i = 1; i <= ar.nups && (name = lua_getupvalue(L, -1, i)) != nullptr; ++i )
@@ -740,7 +741,7 @@ XNode *LuaHelpers::GetLuaInformation()
 		XNode *pConstantNode = pConstantsNode->AppendChild( "Constant" );
 
 		pConstantNode->AppendAttr( "name", c.first );
-		if( c.second == truncf(c.second) )
+		if( c.second == std::trunc(c.second) )
 			pConstantNode->AppendAttr( "value", static_cast<int>(c.second) );
 		else
 			pConstantNode->AppendAttr( "value", c.second );
@@ -1177,7 +1178,7 @@ LUA_REGISTER_NAMESPACE( lua )
 /*
  * (c) 2004-2006 Glenn Maynard, Steve Checkoway
  * 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
@@ -1187,7 +1188,7 @@ LUA_REGISTER_NAMESPACE( lua )
  * 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