Add handy FragmentShader and VertexShader subclasses of Shader.
Add ResourceHandle.asVertexVertexMesh().
Update envsetup to tag v1.4.5.
Throw in a AbstractSubsystem class.
Add VertexVertexmesh class missing from 1ab4ca408e7c60029b7a21cb4c633f7cea24345d.
Split out Entity's input handling into an InputFacet.
Clear out some lint warnings in the Android stuff.
Update stuff for the InputFacet changes.