Git commits in Moodle 3.2.2 by Jonathan Champ

commit 1af3d13bf3551151c661148fb704db22ace5b1b0
Author: Jonathan Champ <jonathan_champ@ncsu.edu>
Date:   Sat, 17 Dec 2016 01:20:45 +0800
Tag:    v3.2.2

MDL-57427 cache: Use perfdebug only when enabled