[WDR] complete overhaul after relaunch of the site

[WDR] complete overhaul after relaunch of the site

The WDR relaunched their site on 2016-02-23 which not only changed the
URL-schema completely but also the layout of their pages.

Apparently the whole "mediathek" now runs on the wdr-domain, so no
separate URL for funkhauseuropa anymore.
There seems to be no explicit handling of video-sizes on the page or in
the URLs anymore. There seems to be only one size for HTML5, but still
several sizes for flash. The extractor adds all to the list of formats.

There is no metadata for the HTML5-stream, so that the best flash-stream
will always be considered as the "best" format. At least in my tests
this seemed to be true anyway.