Developer credits
Git commits in Moodle 2.1.x by David Penner
commit c3b0e64d811dd74dedd6c8c50855cf11ed0b37e0 Author: David Penner <contributor@tracker.moodle.org> Date: Wed, 18 Jan 2012 11:19:27 +0800 Tag: v2.1.5 MDL-31160 block_navigation: Fixed incorrect thrid arg to substr.