Git commits in Moodle 3.0.5 by Kevin Wiliarty

commit 45294e503e7bac778f05fea737f9712c4010529e
Author: Kevin Wiliarty <kevin.wiliarty@gmail.com>
Date:   Wed, 27 Apr 2016 01:18:43 +0800
Tag:    v3.0.5

MDL-54620 ratings: display '0' when aggregate = 0