Special event processing for LastChange events

--HG--
extra : rebase_source : d79713bd55186a54bfc844a840da3ae49c083ca4
Added item_id property to Sonos' playlist class

The original commit was made by David "DPH".
Made possible to create a Sonos' playlist

Allowed the creationg of new Sonos' playlists.
Made possible to add tracks to a Sonos' playlist
Fixed pylint errors and warnings
Updated inline documentation
Code refactoring

Renamed `add_track_to_sonos_playlist` to `add_item_to_sonos_playlist`.
Added container data type for search and browse
Added pylint disable messages for new pylint version, possibly pylint bug
And a python3 fix
Make search container inherit from list. Change deprecation warnings to actual warnings
Merge pull request #203 from KennethNielsen/search_and_browse_objects

Added container data type for search and browse
Fixed broken test
Merge pull request #198 from flavio/sonos_playlist_write_operations

Sonos playlist write operations
Add Queue data structure and implements its use in core. Refactor container objects for more code reuse.
Doc string update after container object change
Merge pull request #214 from KennethNielsen/queue_object

Queue object
Merging with master
Camel to underscore var names, and some more docs
Updating tests for camel_to_underscore conversions