Trimmed big title
Updating assets

Lots of small tasks to implement a more organized asset structure:

- Moved _less to assets/_less.
- Updated rake task (`rake less`).
- Added font-awesome and bootstrap cloned from GitHub.
- Fixed font-awesome's path to find fonts (`@FontAwesomePath`).
- Cleaned onox.less and variables.less.
- The images/ directory is located under assets/ now.
- Removed font-awesome CDN call from <head>.

Now everything should work with `rake less`.