Cleanup of PlaybackController to be more specific on the current track and
moved those functions to TracklistController, which may control all related
to the tracks. Updated tests too.
Converted tracklist_position() to be called with the track one wants to have information of,
/mopidy/frontends/mpd/protocol/status.py@189 should be checked for gathering a value before
the rest.
Correcting some self-arounds that were innecesary.
Converting tl_track_at_eot property in function with the track having to be
given as an argument
Converting tl_track_at_next into a function that takes the track argument.
Rewrote tests too.
Refactoring code to convert tl_track_at_previous() in a function, also recoded
tests.
Created a TracklistController to let it control wether if a track must be consumed or not
Changed mark_consumed to a flexible mark() function that currently allows to mark songs as consumed (that have been played full time), played (that have been played for some time) and unplayable
Ignoring editor temporary files
docs: Documenting changed and created functions
Merge branch 'develop' into tidy-up-core
docs: Updating changelog.rst to reflect updates in core
core: Moving the trigger activation from one playback to tracklist
Renamed tl_track_at_* to more readable names
format: Correcting flake8 messages
core: Merged tracklist_position to index inside TracklistController
docs: Updated changelog.rst
tests: Removing accidental print statement in testcase
Merge branch 'develop' into tidy-up-core

Git was not correctly identifying the merge and threw a conflict
mpris: Correcting get_CanGoPrevious to get() the future instead of passing it.
The failure was invisible to testcases
docs: Documenting further the TracklistController functions