YoutubeIE: new algo for length 86 (fixes #1156)

Now is using the same length as the flash player used for age protected videos, but the algorithm is different, so now for age protected videos it first tries to use the old algo.
YoutubeIE: with age protected videos, add a missing "return" to return the signature decrypted with _decrypt_signature
release 2013.07.31
Switch some calls to to_stderr to report_error and report_warning
Log a better error message if ffprobe or avconv are not found (related #1134)
Allow to download from m3u8 manifests with ffmpeg

They are detected by the extension of the url.
[youtube] Add support for downloading videos with hlsvp (fixes #1083)

They are downloaded with a m3u8 manifest, they seem to be encrypted, but ffmpeg can handle them.
Fix regex error when only subtitled video is available on arte.
Merge pull request #1161 from meyerd/master

Fix regex error when only subtitled video is available on arte.
add support for download YouTube 3d format of 3d content
Merge pull request #1163 from xanadu/master

add support for download YouTube 3d format of 3d content
[youtube] show which formats are in 3D with "-F" and in the format field
[youtube]: new algo for length 83 (fixes #1164)
release 2013.08.02
[youtube] don't crash in verbose mode if 'ad3_module' is not defined in age protected videos (fixes #1159)
Add an extractor for Ooyala (closes #833)

Only works for some sites, it doesn't work for videos that use a f4m manifest
[myvideo] add support for videos that place the video info inside www.myvideo.de/service/data/video/{id}/config (fixes #616)
Merge branch 'master' of git://github.com/rg3/youtube-dl