Git commits in Moodle 2.8.9 by Eric Merrill

commit 287e6a9772ae2985c73becf0aabf64fc01682b5a
Author: Eric Merrill <merrill@oakland.edu>
Date:   Wed, 07 Oct 2015 19:15:00 +0800
Tag:    v2.8.9

MDL-51500 navigation: Compute links with destination context

commit 5c66e986ee7709c606e659b742a9f5232eac979b
Author: Eric Merrill <merrill@oakland.edu>
Date:   Tue, 06 Oct 2015 23:30:00 +0800
Tag:    v2.8.9

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