fixit.js rewrite to use event delegation

All events are now caught with .on() rather than being fired through
callback (bye bye callback hell).
Major CSS rewrite

- Got rid of silly manual box resizing
- Simplified class and ID names
- Defined new classes for form elements
- Textarea resizes vertically without messing up the comment div
Converted units to from px to em
Reverse the order in which comments are displayed

Also display name and date/time when comment was submitted
Added form validation and submit errors

- When textarea is empty on submit, an error is shown
- If name is empty, Anonymous is used
- Use a transparent background loader
Show fixit icon on hover; add tooltip