Refactor, added functionality, fixed bugs

Major refactor in order to understand the code for myself. 
- Added addEventListeners for all events.
- Added removeEventListeners for all events.
- Added unbind() method to clear listeners.
- Refactored into global Grande namespace.
- Added event that fires on changes, which can be listened to by others.
- Renamed some functions and organized in groups.
- Documented some lines.
- Fixed some bugs regarding Toolbar not closing properly.

I certainly don't expect you to take onboard these changes, but I thought I'd share. I really like your plugin grande.js - it's by far the most versatile and stable plugin for lightweight (and beautiful) text-editing. I'm using it for a project, and I needed some of the added functionality, especially removeEventListeners().