new theme "full_screen". full width with the option of having multiple columns

Resubmitted due to tidying up.

Its a clone of the pfsense_ng theme.

Changes:

all.css:
- edited css to take up full width

loader.js:
- added jQuery to display new buttons (add/remove) columm.
- added jQuery to create new columns
- added jQuery to create delete columns

index.php:
- amended to display multiple columns if using this theme

before:
![old](https://f.cloud.github.com/assets/4223752/565197/2bd459d6-c5ee-11e2-901f-740cecc06fa7.png)

full_screen theme:
![new](https://f.cloud.github.com/assets/4223752/565198/3603187a-c5ee-11e2-9a99-5ada4fd94eae.png)