Facia tool: copy/paste

Allows copy/paste as an alternative to drag/drop. Works across separate windows. 

![fronts-tool](https://cloud.githubusercontent.com/assets/1147913/3656506/46048bf6-1187-11e4-9a40-78ec73563206.png)

It stops the click from bubbling to ancestor elements. Needed because the container of articles is clickable (to allow pasting directly into it), but the article elements are clickable also (to allow pasting at their list position).