Developer credits

Git commits in Moodle 2.5.1 by Ankit Agarwal

commit 4f61afa0b78d54896973abf68a69155e7eacc175
Author: Ankit Agarwal <ankit@moodle.com>
Date:   Fri, 21 Jun 2013 10:47:38 +0800
Tag:    v2.5.1

MDL-40250 phpunit: Add unit tests for core_files_external::upload()

commit d8d0b8b39001e6cd07737680c4f97ab0e64322a6
Author: Ankit Agarwal <ankit@moodle.com>
Date:   Mon, 29 Apr 2013 16:53:15 +0800
Tag:    v2.5.1

MDL-39363 scorm: Accept 0 as a valid score