This function returns the average count of tracks that have been played,
and not the average count of all tracks.
Implements #29: Efficiently calculate average play count of tracks
Signed-off-by: Anna Schumaker <Anna@OcarinaProject.net>
Load all tag databases with the new load function.
Implements #15: Load track database through an idle task
Implements #16: Load library database through an idle task
Implements #17: Load genre database through an idle task
Implements #18: Load artist database through an idle task
Implements #19: Load album database through an idle task
Signed-off-by: Anna Schumaker <Anna@OcarinaProject.net>