Converted default theme to Bootstrap 3

Hi,

Today I redesigned the default theme of jobberBase to Bootstrap 3. The main advantage is to make it easier to change the default theme and adapt it to your needs. Another benefit is that this theme will make jobberBase responsive. 

- Responsive layout
- Included most recent versions of
  - Bootstrap (3.1.1)
  - jQuery (2.1.1)
  - jQuery Validation (1.12.0)
- [Bower](http://bower.io) ready
- I used the default Bootstrap styles as much as possible. Very little custom CSS was added.
- It's easy to change to a [Bootswatch](http://bootswatch.com/) themes
- jQuery Validation messages are now localized (based on current environments locale)
- Changed directory structure, and simplified some templates

The theme is Bower ready, but I included all packages to keep installing jobberBase simple. Maybe it's a good idea to strip the included packages down to minimal size?

Before:

<img src="https://cloud.githubusercontent.com/assets/2102973/3236100/001ef496-f0da-11e3-87bc-1bcebb4ef84f.png" alt="alt text" width="45%"> - <img src="https://cloud.githubusercontent.com/assets/2102973/3236169/d8123b1a-f0da-11e3-87ce-45177735cdbd.png" alt="alt text" width="45%"> 

After:

<img src="https://cloud.githubusercontent.com/assets/2102973/3236149/94f3dfa0-f0da-11e3-8581-3f108cab4e79.png" alt="alt text" width="45%"> - <img src="https://cloud.githubusercontent.com/assets/2102973/3236172/e4169212-f0da-11e3-972a-9ca881c42c3b.png" alt="alt text" width="45%"> 

TODO:
- [X] Test responsiveness of all pages on different devices
- [X] Find bugs