fixes #2721
[UstreamIE] [generic] Added support for Ustream embed URLs (Fixes #2694)
Apparently, CSpan switches between single-file and multiple-file results. Either one is fine as long as we get the full four hours.
Maybe the internal ID is more precise, but it's totally confusing, and the obvious ID still allows a google search.
Either one or two spaces is fine here.
The re engine does not want to repeat an empty string, for fear that something like (.*)* could be matching the tokens ... "" "" "" "" "" "" Of course, that's harmless with a question mark, although still somewhat strange.