M(ulti-platform)ANGLE effort

Starting in early 2014, the ANGLE team has begun work on refactoring the code with the goal of supporting translation to desktop OpenGL. The new purpose of ANGLE will be provide a consistent OpenGL ES and EGL context on as many platforms as possible.

The design doc is available [here] (https://docs.google.com/document/d/17mxRfzXuEWyvGM3t2KqVY4svvfRj_GzysOEpmnDpqeo/edit?usp=sharing).