InfoExtractor: add some helper methods to extract OpenGraph info
Use re.DOTALL by default when searching OpenGraph properties
Merge remote-tracking branch 'jaimeMF/opengraph'
Improve OpenGraph property matching
[instagram] fix uploader_id detection (Fixes #1038)
[instagram] really fix uploader_id detection (Fixes #1038)
Strip hash info from URL when making requests (Fixes #1038)
Add LivestreamIE (closes #1042)
[livestream] fix import statement
[mtv]: rework MTVIE and add tests (closes #913)

It uses the same system as ComedyCentralIE to transform ramp urls into http.
Implement format selection in YoutubeDL

Now the IEs can set a formats field in the info_dict, with the formats ordered from worst to best quality. It's a list of dicts with the following fields:
* Mandatory: url and ext
* Optional: format and format_id

The format_id is used for choosing which formats have to be downloaded.

Now a video result is processed by the method process_video_result.

Implemented in TEDIE.
ArteTV: implement multiple formats
Implement the max quality option in YoutubeDL
Do not handle format selection for IEs that already handle it
Default 'format' field to {width}x{height}

If width is None, use {height}p and if height is None, '???'
ComedyCentralIE: use the new format selection system.