Adding media encodings query + 1 fix

Added the ability to query media encodings with #media_encodings method.

Limelight API now paginates data in order to increase return speed. #list_channel_media, therefore, was not pulling in all media.  I have updated the method to add additional optional arguments of page_size and page_id in order to support pagination.

Added #analytics_for_channel method for pulling up channel analytics including total play time.

There will probably be other pull requests as our usage needs increase. Please let me know if you would like these to be handled differently.