new theme "pfsense_ng_fs" & allow themes to add / delete additional widget columns

@rbgarga

Creates a new theme called 'pfsense_ng_fs' a clone of the pfsense_ng theme but is amended to take up the width of the window.

Commit ca794dd simply copies all files from the 'pfsense_ng' folder into a new theme folder 'pfsense_ng_fs'

Changes:

pfsense_ng_fs/all.css:
- edited some css to make the theme take up the windows full width

pfsense_ng_fs/loader.js:
- added jQuery to display new buttons (add/remove) columm.
- added jQuery to create new columns
- added jQuery to delete columns

index.php:
- amended to display multiple columns if a theme names ends in '_fs' (it would require the jQuery I have used in loader.js to be present in the themes folder).
- the changes in index.php should not have any affect on the other themes UNLESS the themes name ends with '_fs'