SAK-25778 changes based on code review

git-svn-id: https://source.sakaiproject.org/svn/content/trunk@307541 66ffb92e-73f9-0310-93c1-f5514f145a0a
SAK-25887 - use modernizr to determine if highlight DnD or standard upload interface

git-svn-id: https://source.sakaiproject.org/svn/content/trunk@307542 66ffb92e-73f9-0310-93c1-f5514f145a0a