Merged Phillipe Rollin's (@prollin) RenderTarget changes.
Using the new GraphicsCapabilities propertys for Depth24 and NonLinear. Set the right Depthformat when calling GL.RenderbufferStorage()
Change GraphicsCapabilities properties to have Supports prefix.
Fixed SupportsPackedDepthStencil typo.
Fix typo for Anisotric to Anisotripic, for non GLES codepath.
Fixed MacOS build DepthFormat.Depth24Stencil8 path in RenderTarget2D
Bizarrely the previous commit built fine locally, but not on the build server. I've added a missing the break;
Merged with upstream and fixed conflicts.
Removed Check and used @prollin's GL.FramebufferRenderbuffer code as per discussion.
Merge pull request #1699 from CartBlanche/AndroidFullScreenFix

Merged Phillipe Rollin's (@prollin) RenderTarget changes for Android
Merge pull request #73 from mono/develop

Merge back from develop