reposition_item

Description:

public void reposition_item (MediaItem item, int index)

Change position of one MediaItem within the queue.

Note that the index is the new position you expect item to be after whole reposition operation is finished.

If item is not in the queue, this function will do nothing.

this	a Queue
item	a MediaItem
index	the index to place `item` in queue, -1 to place at the end