Upgrade Bootstrap to 3.2 & tweak admin interface.

- Upgrade the markup throughout to use the new Bootstrap class names

- Update CSS and HTML for Devise forms

- Redirect to admin sign in page when not signed in

- Allow admin name to be updated

- Redirect to edit account page after updating

- Remove duplicate Devise views, except for the confirmation instructions email, which uses a Custom Mailer that sends the appropriate email based on the user type (developer or admin).

- Shorten link text in nav bar

- Remove "Sign in" and "Sign up" links from nav bar because they're redundant

- Rename "Home" link on developer portal to "Ohana Developers" (needs to be localized)

- Refactor Devise custom registration to use separate controllers for each model