[WIP] add ownership changes to the editor tools (bug 712682)


Fixes [bug 712682](https://bugzilla.mozilla.org/show_bug.cgi?id=712682)

Misses tests:
- for the display of the user changes to the editor tools
- for the sending of emails to authors of the addon


![screen shot 2014-12-24 at 16 43 53](https://cloud.githubusercontent.com/assets/167767/5549635/f1a76c78-8b8d-11e4-86a1-f13045fe7896.png)
Even [double (white)spaces](http://practicaltypography.com/one-space-between-sentences.html) within comments? ;)