Added stencil buffer to FrameBuffer.
Added matching constructor to existing code.
Merge branch 'master' of github.com:libgdx/libgdx
Added a test for stenciled framebuffer.
Removed unneccesary changes.
Removed unneccesary matrix and added a comment what should be seen.
Merge pull request #2338 from ollipekka/master

FrameBuffer to include stencil attachment