Windows build update.

git-svn-id: https://www.libavg.de/svn/trunk/libavg@9256 44470bb9-56e9-0310-a0f8-c586564d3dc6
Disable all shaders with non-trivial loops if shaderusage == minimal.

git-svn-id: https://www.libavg.de/svn/trunk/libavg@9257 44470bb9-56e9-0310-a0f8-c586564d3dc6