Add Backbone collection and model!

Yay!
The background page creates a collection and fetches its content from
localstorage. Then scrapes the queue page and adds or updates models,
which are automatically saved to localstorage.
The popup page creates a Queue collection and fetches from localstorage
as well. This collection is used to create the elements.
Fix badge number when resetting seen state
Merge branch 'master' into backbone

Conflicts:
	src/js/background.js
	src/js/popup.js
	src/manifest.json
Merge branch 'master' into backbone
Complete use of Backbone in background and popup

Refactor of badge update so it's centralized in one place
Update version and slight tweak when clicking notification