* Allow URLs that have a 'subdirectory' before the actual program name, e.g.
'xyz/xyz-episode-1'.
* The author and broadcastDate fields in the XML file may be empty.
* Add test case for the two problems above.
Extractor for videos from the Bayerischer Rundfunk Mediathek[1]. Currently only
supports videos. Audio and podcasts do not work yet with this extractor.
1: http://br.de/mediathek