Basic XMLTV support

- XMLTV feed - Fixes #60

  Example URL: http://localhost:8000/xmltv/frikanalen.tv_2014-03-01.xml

- Some new settings in base.py for the feed

  Maybe this should become a new model for configuring multiple channels

- Some changes for making url-names consistent
- A check to avoid repeatedly adding to the sys.path (when debugging?)
- Minor changes to the video management, still not done