XErrorDB in a modular world

[Alan Coopersmith]

This bug notes that the requests and error codes for XFixes are
not in XErrorDB:
	https://bugs.freedesktop.org/show_bug.cgi?id=3021

This brings up another question - how should XErrorDB be handled
in a modular world?   The current module of having a single file
in xc/lib/X11 listing all the codes for all the extensions doesn't
seem to fit well with extensions each being delivered separately.

What if XErrorDB as a single file was replaced with a directory
in which each extension installs it's own file as part of it's
protocol module and the original XErrorDB was used for just the
X11 core protocol entries?

Are there any other files like this that people can think of would
need similar handling?

	-alan-