I keep using the queue_iter struct for now to reduce code churn in this
patch. I'll be replacing it in the next patch.
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>
I also take this chance to add extra functions for directly manipulating
the current track, since this is something we do fairly often.
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>