fixes #17153: don't call preventDefault for AUDIO or VIDEO elements as this prevents playing the media file on some devices (commit to 1.9 branch). Thanks Sebastien Pereira (IBM, CCLA). !strict

git-svn-id: http://svn.dojotoolkit.org/src/branches/1.9/dojo@31441 560b804f-0ae3-0310-86f3-f6aa0a117693