Exit if textures could not be loaded
Strip png metadata
freetype-gl: remove win32 special case

Do not include wglew.h directly; it is an internal header.
Move PocoFoundation after PocoUtil in link order

Fixes static linking (PocoUtil needs symbols from PocoFoundation that
are otherwise eliminated by the linker in the original link order).
Add SDL2{,_image} dependencies for static linking
Set Poco and GLEW to static linking on Win32