13352: Fix for ETHREEOH-1216: Line breaks in forums posts from earlier earlier versions don't work
- Added <br/> to list of safe tags so that old forum posts containing it render properly
- Edit post dialog updated to replace <br/> tags as well as <br> when editing
git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@13354 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261