[bliptv] Fix resolution of lookup id in some videos

In some videos (for example, http://blip.tv/play/gbk766dkj4Yn) resolving
lookup id would fail, because page at
http://blip.tv/play/gbk766dkj4Yn.x?p=1 would have no "config.id" in
it. Fixed by requesting different URL and inspecting the URL which the
client is redirected to.
[bliptv] Fix \n\n at the end of real_url

See https://github.com/rg3/youtube-dl/issues/3544#issuecomment-53166516
Merge pull request #4333 from ymln/bliptv-fixes

[bliptv] Fix some videos not downloading