Merge branch 'hotfix/docs'
Merge branch 'release/1.7.5'
Merge pull request #337 from papplampe/develop

Add a plugin for Chaturbate
plugins.ustreamtv: Fix missing transcode streams.

If a transcode is the same resolution as the source stream
it does not get added to the list of streams.
cli: Add a --http-ignore-env option.
cli: Add a --no-version-check option.

Resolves #323.
cli: Add --retry-streams and --retry-open options.

Resolves #333.
stream.flvconcat: Make sure audio and video tags are synced.

This is done simply by discarding tags until both
audio and video headers have been encountered.
stream.flvconcat: Set sync_headers to False by default.

Otherwise audio only streams will not work.
plugins.ustreamtv: Download segments fully before processing.

Attempts to work around a issue in requests where
timeout is not applied to streaming requests.
stream.flvconcat: Handle non-AAC/AVC header syncing.

Only AAC and AVC will tell us if a tag contains a
header or not.

While MP3 seems to work fine without specifically
waiting for a header, there might be problems with
other codecs.
plugins.ustreamtv: Change the way chunk info is fetched and processed.

Make it behave more similar to the way HLS works,
by fetching the chunk info as needed instead of relying
on the RTMP server to give us the info in a timely fashion.
stream.flvconcat: Dynamically handle timestamp gaps.
plugins.youtube: Handle embed URLs.

Resolves #341.
Support Be-at.tv

Resolves #216
Merge pull request #342 from athoik/beat

Support Be-at.tv
plugin.api.http_session: Make sure a read timeout is set.

requests 2.0 changed the read timeout behaviour,
but it will be fixed in the future 2.3.0 release.

This fix uses a HTTPAdapter if needed that will
make the behaviour consistent on all versions.
tests: Python 2.6's unittest module is terrible.
plugins.ustreamtv: Fix incorrect max chunk range.
stream.hls: Download segments fully before writing to output.