Git commits in Moodle 3.0.4 by Michael Aherne

commit ad23f18a4011721e6371302594477f244e2e2aab
Author: Michael Aherne <michael.aherne@strath.ac.uk>
Date:   Fri, 26 Feb 2016 22:11:40 +0800
Tag:    v3.0.4

MDL-53256 cache: Prevent overwriting of cache config with invalid data