This pointer can be used immediately by testing code instead of simply
looking at the return status.
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>
Putting this code in a new file helps make gui/playlist.c less complex,
and better matches the organization of files in core/
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>