Adding desktop notifications

not configurable at this point, but Chrome lets you do that.
Still some issues with the size of the image in the notification..
Some cleanup and using bigger thumbnail image

in the notification though, the bigger image sometimes doesn't show up.
It will likely be fixed once I use data URL instead of the actual image.
Using properly-sized thumbnails for desktop notifications

Basically, according to this page
https://code.google.com/p/chromium/issues/detail?id=340241#makechanges
images in desktop notifications needs to have a 3:2 ratio.
Hulu's images are not that ratio so I need to create a data URL with
canvas.
Add action and tracking for closed and clicked notification

when clicked it opens the show, when closed it marks the show as seen.
Increase version number for store release
Merge branch 'master' into backbone

Conflicts:
	src/js/background.js
	src/js/popup.js
	src/manifest.json