Git commits in Moodle 3.1.0 by Jetha Chan

commit 623c947f2b0ac41b5cd489701c3411a1f6be5ff3
Author: Jetha Chan <jetha@moodle.com>
Date:   Tue, 09 Jun 2015 17:12:31 +0800
Tag:    v3.1.0-beta

MDL-37308 files: support transparency when not resizing; new unit test