Git commits in Moodle 2.2.x by David Penner

commit 5a479aa6286c72c6b00bfd8f19ee32e740c0f9e6
Author: David Penner <contributor@tracker.moodle.org>
Date:   Wed, 18 Jan 2012 11:19:27 +0800
Tag:    v2.2.2

MDL-31160 block_navigation: Fixed incorrect thrid arg to substr.