Git commits in Moodle 3.1.0 by Jonathan Champ

commit ddf98ccac392863b8d58d557846cb7ed1b27c89f
Author: Jonathan Champ <jrchamp@ncsu.edu>
Date:   Thu, 03 Mar 2016 12:33:15 +0800
Tag:    v3.1.0-beta

MDL-39524 setuplib: Improve get_real_size() performance and readability