glestrace: Framework for GLES tracing library

This patch provides a framework for tracing GLES 1.0 and 2.0
functions. It is missing a lot of features, but here are the
things it accomplishes:

- Stop building the glesv2dbg library, and build the
    glestrace library instead.
- Replace the hooks for glesv2dbg with the ones for glestrace.
- Add the basics for the trace library. Currently, this
    traces all GL functions, but not all required data is
    sent for all the functions.  As a result, it will not
    be possible to reconstruct the entire GL state on the
    host side.

The files gltrace.pb.* and gltrace_api.* are both generated
using the tools/genapi.py script.

Change-Id: Id60a468f7278657f008bc6ea1df01f9bdfecfdd3