Add support for southpark.de
The videos expire.
* Do not accept '>' between the property and content attributes. * Recognize the properties if the content attribute is before the property attribute using two regexes (fixes the extraction of the description for SlideshareIE).
The ajax pages are empty, now it looks directly in the channel's /videos page
Some tracks are not in mp3 format, they can be wav files.
The two versions use different systems.
Suggested in #1743