bugzilla-to-webcompat von ksy36

The button is added to the top button group on a bug page. Upon clicking on the button the following changes are performed:

1. A copy of the bug is created on webcompat.com
2. A link to webcompat issue is added to "See also" bug field
3. Bugzilla issue is closed as "Resolved > Moved"

Note that the addon will only work for users who can edit bugs on bugzilla