urplay: add support for the new site

some help from @unayok
urplay: adding support for ur.se
download_hls: add support for relative urls
expressen: it works now again.
Support for radioplay.se
Generic class a way to find embeded videos

support for embeded svtplay videos.
urplay: use rtmp instead of hds
download_rtmp: add a dot before extention and after filename
download_hds: dont hardcode metadata size.
download_hds: fix some decoding problems

Saw some issues while downloading streams from urplay.
download_rtmp: work around for a bug in python2.7

python2.7.2 in OSX Mountain Lion has bug in shlex.split().
see http://bugs.python.org/issue6988
Adding few subtitle formats.

json, sami, smi and wsrt
urplay: support for subtitles
svtplay: support for subtitles
tv4play: support for subtitles
kanal5play: support for subtitles
kanal5play: support for kanal9play.se
kanal5.se is now "closed"
viaplay: support for subtitles
justin.tv: write an error message when we cant find any streams