Developer credits
Git commits in Moodle 2.9.0 by Wesley Situ
commit 7be4cf1873e01f144f461a996a821cfcd259d1b8 Author: Wesley Situ <wsitu@oid.ucla.edu> Date: Wed, 21 Jan 2015 03:27:36 +0800 Tag: v2.9.0-beta MDL-48916 atto_undo: Clarify text for "Undo/Redo"