ANDROID: Don't install source files to apk

If ant is let loose on backends/platform/android it copies everything it can into the final apk file, which we obviously don't want. This changes it so that it will only see the java files which it compiles puts the results into the apk.
GRIM: Add a constructor for Shadow

This lets us get rid of the loop in Actor and lets us ensure
that Shadow is initizlied even if constructed elsewhere.
GRAPHICS: Stencil for grim shadows [OpenGLS]
GRAPHICS: Transpose view/model matrices correctly
GRAPHICS: Add shadow mode to grim actors [OpenGLS]