specs/scripts: Cleanup.
specs/scripts: Initial version of XML to *api.py conversion.
egltrace: Update egl enums.
glxtrace: Update GLX enums.
glretrace: Remove bogus retrace_wgl* stubs.

Most of these are not properly implemented, so it's better to warn about
it than silently fail.
glretrace: Don't replay failed WGL calls.
eglretrace: Workaround crashes when recreating EGL surface.