egltrace: Add GL_EXT_texture_storage entrypoints

Prototypes obtained through:

  specs/scripts/gltxt.py http://www.khronos.org/registry/gles/extensions/EXT/EXT_texture_storage.txt

Issue #184.
glxtrace: Add GLES prototypes too.

Some applications seem to fail to distinguish GLES and GL entrypoints
apart.  To have complete traces in that situation, generate wrappers
for both GLES and GL prototypes.

Issue #184.