bbcode: Don't use a preview picture in the "attachment" element if it is a video attachment.
Notification by mail: Improvement for the threading of notifications, new headers to support filtering.
Reduced options when adding a friendica contact and an address was provided via URL parameter.
If a user is already connected to another user, then don't show the "connect" link on his profile.
Provide a parent in the notification, so that threading of the notification mails is working.
Vier: Some more design changes to "plus" style.
Merge pull request #1072 from annando/master

Less visible options when connecting a friendica contact