Remove stray require_once of GlobalFunctions.php from EditUser extension's setup file (added in
r43509 to support an incorrectly placed wfDebug() call which has long since been removed)
Apparently violating MediaWiki's operating assumptions here was in some circumstances causing breakage due to wfDebug() being updated to include hooks calls:
http://www.mediawiki.org/wiki/Special:Code/MediaWiki/88843#c17219