[COMMIT] Merge regexp-opt.el with GNU, fixing bugs and adding improvements

[Stephen J. Turnbull]

Switching to xemacs-beta.

Aidan Kehoe writes:

 > 2008-01-11  Aidan Kehoe  <kehoea at parhasard.net>
 > 
 > 	* regexp-opt.el: Merge revision 1.34 from GNU, of
 > 	2007-01-21. Thank you GNU.

This is pre-GPLv3, right?

Please say explicitly that you've checked that it's GPLv2 in all
merges from GNU until we go to "GPLv3 or later" ourselves.