Added Drafts and Published tabs to separate tweet inspirations you're working on and those you've already published.

Added Copy to Tweton button that let's you select any text inside Twitter and copy it to the Tweton editor.

- progress indicator on save and delete
- edit notes
- style expanded Tweton area
- dynamically expand the textarea
- expand/collapse icon to match font color
- add confirmation before delete
- add usage instructions to popup page

- new feature: store sidebar state in localStorage
- fix: reset loading spinner after sign-in

Better of use of screen real-estate.