* Put youtube API functions under the YoutubeAPI namespace
* Implement the following endpoints:
- `next`
- `player`
- `resolve_url`
* Allow a ClientConfig to be passed to YoutubeAPI endpoint handlers.
* Add constants for many new clients
* Fix documentation of YoutubeAPI.browse(): Comments and search
result aren't returned by the browse() endpoint but by the next()
and search() endpoints, respectively.
* Accept gzip compressed data, to help save on bandwidth
* Add debug/trace logging
* Other minor fixes
Cherry picked from ui overhaul branch with a few modifications:
- channel folder is renamed to channels
- parsing for channel home and featured channels are removed due to
lack of infrastructure from other commits
(cherry picked from commit 44d18b8e14)
