add xpi to repository

don't keep strong references to observers

remove forcing the toolbarbutton to the navbar

Switched to using ActionButton api

step 1 of getting Cheevos to work with the updated SDK

Merge pull request #23 from sirodoht/master

Updated Greek locale

Added an API for other add-ons to award achievements.

Added 'Cheevos They're Great' achievement

Added missing silver and gold award for Super User

Removed reference to the 64x icon since it had a slighlty worse color hue than than the AMO-hosted icon.

Bumped version to 1.5 and added a reference to the 64x64 icon.

News Junkie achievement

Don't award achievements for page visits if the visit is inside of a private window.

Now using new Private Browsing APIs