GenericIE: Detect videos from Brightcove

Brightcove videos info is usually found in an <object class="BrightcoveExperience"></object> node, this is passed to a new method of BrightcoveIE that builds a url to extract the video.
Set the playlist_index and playlist fields for already resolved video results.
BrightcoveIE: add support for playlists
GenericIE: detect more Brightcove videos

In some sites "class" contains more that BrightcoveExperience
added an IE for Ehow videos
added test for ehow
Merge remote-tracking branch 'yasoob/master'
[ehow] improve minor bits
Remove video_result helper method

Calling it was more complex then actually including the type in the video info
Add helper function find_path_attr
[arte] Fix on 2.6
[brightcove] fix on Python 2.6
[brightcove] add import
GametrailersIE: support multipart videos

Use xml.etree.ElementTree instead of re when possible
YoutubeIE: a new algo for length 83
release 2013.07.11
YoutubeIE: add algo for length 81 (closes #1026)
release 2013.07.12
Add IGNIE

Only for www.ign.com, it doesn't support country specific versions (like es.ign.com)
[ign]: support some country versions and add an extractor for 1up.com

1up.com uses the gin video system, the extractor is a subclass of IGNIE, it just replaces the video id