Git commits in Moodle 2.3.0 by Ray Guo

commit 8e6530d897cc75626b62c99ccf4b8d38310057ad
Author: Ray Guo <r.guo@open.ac.uk>
Date:   Tue, 03 Apr 2012 21:38:47 +0800
Tag:    v2.3.0-beta

MDL-29174 Remove the empty modulename_extend_navigation() stub from 7 modules.