Started restructuring parsing system
Base "explore" structure
Completed parser restructure, working Explore.new_releases() method

 - Explore.new_releases() method
 - Tungio parsers for Artist, Album and Image objects
 - Cleaned up [mecury.request] and MercuryJSON parsers
Implemented [Explore] featured_playlists and top_playlists, added tunigo playlist parser
Merge branch 'feature/explore' into develop
Catch exceptions in [Uri.to_gid]
Fixed bug in mercury response parsing
Fixed protobuf parsing
Fixed issue with MercuryRequest returning single items
Fixed issue loading metadata with URIs that contain unicode/utf-8 characters
[Metadata.playlist] convert Uri objects to strings
Fixed bug when fetching playlists with duplicate tracks