The new errdb error code database is more accurate than the regular
expression-based errcode scripts.  This patch removes errcode scripts
in favor of errdb.

The gpxebot.py script is no longer needed, gpxebot has been released
as a separate open source codebase:

  http://git.etherboot.org/?p=people/stefanha/gpxebot.git;a=summary

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>