Git commits in Moodle 3.0.0 by Matt Petro

commit 2351ed55e82c62dba486c7ea45f831186ca0b710
Author: Matt Petro <petro@engr.wisc.edu>
Date:   Tue, 22 Sep 2015 01:44:18 +0800
Tag:    v3.0.0-rc4

MDL-51482 caching: Fix unnecessary updates to lastinvalidation time