Rendering system overhaul

+ XVertexFormat for custom vertex formats
+ XVertex now uses set* to set its values
+ XVertexBuffer is now directly accessible and has extended
functionality
+ Misc. fixes
- XSpriteBatch removed
Merge remote-tracking branch 'origin/master'

Conflicts:
	3rdparty/angelscript/sdk/angelscript/lib/angelscriptd.dll
	3rdparty/angelscript/sdk/angelscript/lib/angelscriptd.lib
	build/Win32/Debug/angelscriptd.dll
	build/Win32/Debug/x2dd.dll
	build/Win32/Debug/x2dd.lib
	build/Win32/Release/x2d.dll
	build/Win32/Release/x2d.lib