Fixed back url verification (#16466).

git-svn-id: http://svn.redmine.org/redmine/trunk@13018 e93f8b46-1217-0410-a6f0-8f06a7374b81
Remove users from cc if they are already notified (#16415).

git-svn-id: http://svn.redmine.org/redmine/trunk@13029 e93f8b46-1217-0410-a6f0-8f06a7374b81
Updates for 2.5.1 release.

git-svn-id: http://svn.redmine.org/redmine/trunk@13033 e93f8b46-1217-0410-a6f0-8f06a7374b81