Fix Youtube streaming #149

[jasper-d]

Changes concerning #149

• Katana host as a local proxy, providing MediaElement with a HTTP stream. For the time beeing it is only used for Youtube but could be used for Soundcloud as well if they decide to enforce transport encryption too.
• Updated Youtube API libs.
• Removed Youtube rating as ratings are no longer provided by the Youtube API.
• Changed the way URLs are customized. Each sub type of Song is responsible for customising it's own URL while only the proxy can create proxy URLs.

Minor changes concerning the Soundcloud API

• Set the limit for the Soundcloud API search to 200. This is the maximum Soundcloud allows. If the limit is omitted, results are truncated after the 10th hit.
• Soundcloud API changed from HTTP to HTTPS as the secure version is orders of magnitudes faster for me

Known issues

• Update Youtube API key #152 is not fixed, you will need to provide a new Youtube API key
• Youtube video streaming does not work #155 Youtube video streaming does not work yet (I have little interest in working on it)

[jasper-d]

API Key...