Delete media files when removed from the app

git-svn-id: http://ios.svn.wordpress.org/trunk@4007 7d847f7c-ffe1-4a24-85be-b788d016d96a
Updated version number to 3.4

git-svn-id: http://ios.svn.wordpress.org/trunk@4008 7d847f7c-ffe1-4a24-85be-b788d016d96a