uses the database to create random playlists of specified size
with the advanced GUI you can..
set the number of songs (up to max playlist buffer)
set the number of tracks before a repeat is allowed
play the tracks when finished
-- fix a parsing bug where first and last entry in database
were corrupted
-- Incremental loading for very large databases, allows decent speed and lower ram usage
Change-Id: Ia95469b6a04625b621129ec61e5db4b2b00adc5e
