Uses a new helper method in InfoExtractor: _download_xml

The website requires SSLv3, otherwise it just times out during SSL negotiation.

[brightcove] Set the 'videoPlayer' value to the 'videoId' if it's missing in the parameters (fixes #1815)

Sadly applications using youtube-dl's python sources can't directly
access it's log stream. It's pretty much limited to stdout and stderr
only.

It should log to logging.Logger instance passed to YoutubeDL's params
dictionary.

Closes #1704

[bandcamp] move the album test to the album extractor and return a single track instead of a playlist

This is the first step towards being able to just import youtube_dl and start using it.
Apart from removing global state, this would fix problems like #1805.