Update d3_rails and jquery-atwho-rails

We were a bit behind on these JS libs, so this updates them.

AtWho made a few API changes for which I had to update our usage.

Should fix #1457 (closed) as well.

Reassigned to @dzaporozhets

Milestone changed to 7.11

@rspeicher looks good. Please make it mergeable and merge by yourself

Added 196 commits:

• f85d62a4...926a8146 - 193 commits from branch master
• af855b57 - Update d3_rails
• d086e76c - Update jquery-atwho-rails
• 85bbb914 - Fix GfmAutoComplete for jquery-atwho 1.0

Status changed to merged

mentioned in commit 3ae31c22