Add correct enumerants for OES_EGL_image_external to glext.h.
SurfaceFlinger now checks for the correct extension name.
Change-Id: I2ba2728a01fa2260bd086d2df4316c68f694a9b1
- changed glTexImage2D() declaration so it matches that of GLES 1.x; otherwise we can't include both headers (!!!)
- added parameter names to the declaration of some extensions (this is needed by glapigen and glentrygen)