Add plugin for mlg.tv.

Resolves #275.
Test for reusing input written to buffer
Fix buffer overwriting issue when piping HDS stream

The HDS module uses “memoryview” objects, which are not “bytearray” objects,
but still need copying.

Simplify by always calling bytes() without checking the type of object. With
a “bytes” object input the time taken is still independant of the size of the
buffer:

Direct bytes() call: 1.8 µs (Python 3.3) or 0.40 µs (Python 2.7)
Instance check: 0.7 µs (Python 3.3) or 0.6 µs (Python 2.7)
Merge pull request #295 from vadmium/buffer

Fix memory overwriting issue caused by buffer rework
Merge pull request #296 from vadmium/master

Fix spelling, ResourceWarning, JSON formatting
Support DMCloud.net

Initial support for Dailymotion Cloud platform.

Currently only HLS implemented, although almost every stream technology supported!

More info here: https://www.dmcloud.net/doc/api/api-streaming.html#streaming-protocols

Example URL (from Action24.gr): https://api.dmcloud.net/player/embed/52efc1ea94a6f6062e60ad33/52f014e506361d2fbfcaf470?auth=1706825743-0-2o6o85nh-f934dd72635591da64ef0fdbe704d738&preset=52efc3e894a6f607a8ca8f65&force_asset_name=mp4_h264_aac_hq&autoplay=1
Merge pull request #297 from athoik/dmcloud

Support DMCloud.net
Add plugin to extract dmcloud embeds.

Currently works only on action24.gr.
DMCloud: Add Support For RTMP Streams
Merge pull request #300 from athoik/dmcloud-rtmp

DMCloud: Add Support For RTMP Streams
plugins.ustreamtv: Add support for password protected streams.

Resolves #298.
Document plain progressive HTTP as a streaming protocol