Remove all the container node stuff from AphrontTagView

Summary: See discussion in D6131, D6130. This turned into 35 layers of mess so throw it away and just tweak the JS to be more flexible.

Test Plan:
  - Clicked "Show More Applications".
  - Clicked "Show Fewer Applications".
  - Edited tasks using popup dialog.
  - Tried to drag tasks using pencil icon (correctly no longer works).
  - Changed threads in Conpherence.
  - Not sure how to actually hit the Conpherence "Load ... Threads" thing since
    it seems to auto-load? But that works, at least, and the code doesn't really
    care what you hit.
  - Added a conpherence participant.
  - Added a new calendar item.
  - Poked around other menus.

Reviewers: chad

Reviewed By: chad

CC: aran

Differential Revision: https://secure.phabricator.com/D6133