vevo - force iOS to use HLS instead of MP4 which seems to fail
L Studio - Ignore 'index' if not found in the XML file
CNN - Small tweaks
Youku - Raise exception if we encounter a http error.
YouTube - Updated sig code from youtube-dl
Initial MTV service changes/update (service also renamed).
Merge pull request #570 from mikedm139/vevo

vevo - force iOS to use HLS instead of MP4 which seems to fail
videovideo - Update available resolutions to match the YT service
YouTube - Update for sig with length 90 (https://github.com/rg3/youtube-dl/blob/master/youtube_dl/extractor/youtube.py#L184)
Vevo - Simplify MediaObjectsForURL; Add artist to video title.
YouTube - Fix '85' sig
Stuff TV - Remove URL Service: site has changed, now using Brightcove.
Internet Archive - Check if 'creator' metadata is present.
CNN - Do not check for specific bitrates/resolutions, find the closest match.
Vevo - Catch geoblocked or otherwise unavailable videos.
YouTube - Fix '87' sig