emulator opengl: add GLESv2 support to driver + renderer

Added GLESv2 library to system.
Made fixes to the host libOpenGLRender to
compile and support GLESv2 (defined WITH_GLES2).
Other fixes required to make GLESv2 to work.

Change-Id: I9eb198e6092e7fa3550342c50929dd1714282cb3
25 files changed