First commit
Improve application look and feel with Twitter Bootstrap

* Add bootstrap css to vendor/assets/stylesheets.
* Add bootstrap images to vendor/assets/images/bootstrap.
* Remove scaffold generated css.
* Change application.css to override some bootstrap classes so that it
  works with the correct path for our images. Also remove #alert
  definition since we'll be using bootstrap messages.
* Update application layout to use bootstrap html structure, and add
  links to the top navigation menu.
* Update jobs/index and jobs/premium views to remove footer links.
* Update jobs/show to use bootstrap styled messages for our flashes.
* Update jobs/_form and comments/_form to use bootstrap's html form
  structure, with horizontal forms - left aligned labels. Also change
  error messages to use the same styled messages as flashes.
Implementação sistema de login