Cleanup auto-completion and add it to all GFM inputs
Created by: riyad
- Extracts static initialization and setup from the notes form and moves them into a JS asset (converted to CoffeeScript)
- Puts the per request initialization into a layout partial
- Moves helper into ApplicationHelper
- Marks all GFM capable inputs as such, so auto-completion works on them, too
- Fixes forms that get added after page load (i.e. per Ajax)