Do not merge! Site change

Do not merge!
Branch will be squashed when new site goes live!

PR created for reference.

Updated against: http://beta.svtplay.se/

Before going live
- [ ] Change BASE_URL in the svt module
- [ ] Update background image
- [ ] Update README and docs
- [x] Decide if BestOfSvt.se should be included or not ("Populärt" and "Sista chansen" are "native" featues now)
- [x] Create settings module for accessing settings via constants
- [x] Move logic to find video URL to SVT module
- [x] Add images to categories #92 
- [x] Add category "Sändningar"
- [x] Convert SVT date format to XBMC date format for proper "aired" support
- [x] Add unit tests for the SVT module
- [x] Add playlist feature
- [x] Add better support for live broadcasts (only show ongoing?)
- [x] Add support for "Kanaler"