An extension to make Goo.gl a little more useful.

Kind of working now, at least as far as labeling goes.

• [X] Add short label to link.
• [X] Add tags to link.
• [ ] Add search bar for finding links by tags/labels/url.
• [ ] Add tag filter.
• [ ] Cloud syncing for links (Google Drive, likely).
• [ ] Ability to share/collaborate on links/tags.