Git commits in Moodle 2.6.4 by Mohamed Alsharaf

commit 015f49d0d363c710eb349d8a2fa06fe457b5353a
Author: Mohamed Alsharaf <mohamed.alsharaf@gmail.com>
Date:   Fri, 11 Apr 2014 07:14:51 +0800
Tag:    v2.6.4

MDL-45192 assign: added behat script & new definitions to handle alert dialog