Defaults/Labels for Qualities/Captions

[jeroen]

For 6.0, we punted on setting publisher/viewer defaults for quality labels and captions tracks. We also punted on setting proper sources/captions in RSS, or paving the way for other types of tracks (thumbnails or captions).

This project adds these functionalities.

• Give publisher the ability to set the player’s default quality level and default caption track/language
• Give the player a mechanism to remember the users' last selected quality level and caption track/language setting
• Set quality and caption labels in RSS

Full spec on Features -> Player: Defaults/Labels for Sources/Tracks