Change target insertion from activityItem to post
Add user marks and display them as fullname
Merge branch 'berlin-add-user-marks' into berlin
WIP
Filter non-replies
Merge branch 'stream_replies' of https://github.com/cosent/plonesocial.microblog into stream_replies

* 'stream_replies' of https://github.com/cosent/plonesocial.microblog:
  Filter non-replies
  WIP