Merge pull request #2 from rg3/master

Update
[RTLnowIE] Add support for http://n-tvnow.de
[RTLnowIE] Allow video description without upload date

Some videos (feature films) have no upload date.
[france2] Add support for URLs without video IDs (Fixes #1547)
release 2013.10.04
[youtube] new static 82 signature
Merge remote-tracking branch 'rzhxeo/rtl_upload_date'
Merge remote-tracking branch 'rzhxeo/rtl_ntv'
[FlickrIE] Fix HTTPS url
Merge pull request #1551 from rzhxeo/flickr

[FlickrIE] Fix HTTPS url
[ted] Prepare #980 merge
Document formats (for #980)
Clarify that url and ext are optional when formats is given (#980)
[mtv] Prepare for #980
[comedycentral] Prepare for generic video extraction (#980)
Merge remote-tracking branch 'origin/master'
[francetv] Use common format for ID of generation-quoi subextractor
[rtlnow] Skip test on travis
[yahoo] Do not try to run rtmpdump on travis
Include length in player cache ID

Some videos use the same player with IDs of multiple lengths.
See https://travis-ci.org/rg3/youtube-dl/jobs/12126506#L319 for an example.