Changes

Bug 925: Use proper common profile and test compatibility for GLContextImpl's default VAO.

Bug 925 - Accept an ES3 Context, if reported via GL-Version-String w/o EGL_OPENGL_ES3_BIT_KHR

Add Quirk 'GLES3ViaEGLES2Config': ES3 Context is used via EGL_OPENGL_ES2_BIT and 'version 2' for create context attributes.

- GLContextImpl.setGLFunctionAvailability(..)'s ES version validation
  only fails if requested major version == 1 and doesn't match.
  Hence requesting major==2 and having version 3 is tolerated.

- GLContextImpl.setGLFunctionAvailability(..)'s Quirks:
    requested-major < has-major -> Adding GLES3ViaEGLES2Config

- EGLDrawableFactory.mapAvailableEGLESConfig(..):
  Reflects has-major version, i.e. GLES3ViaEGLES2Config situation where
  an ES2 request leads to an ES3 version.

Note: All workarounds can be found via lookup of GLES3ViaEGLES2Config (as usual when using quirks).