Git commits in Moodle 2.9.3 by Eric Merrill

commit 02bb527c56269aeacbb1a3c195678ee42cae6a06
Author: Eric Merrill <merrill@oakland.edu>
Date:   Wed, 07 Oct 2015 22:00:00 +0800
Tag:    v2.9.3

MDL-51500 navigation: Compute links with destination context

commit 1f77dcd5b36d60c004e25c729e8d48940c86ab8f
Author: Eric Merrill <merrill@oakland.edu>
Date:   Tue, 06 Oct 2015 23:30:00 +0800
Tag:    v2.9.3

MDL-36606 gradereport: Update AJAX grader to understand gradeless cells

commit f7265106ef84bd6a4eb281539d60f626ec409472
Author: Eric Merrill <merrill@oakland.edu>
Date:   Wed, 23 Sep 2015 05:14:17 +0800
Tag:    v2.9.3

MDL-51501 themes: pix_icon should not include empty alt tags