Playlist acting like history

[Felipe Escoto]

With the current method of handling playlist and opening files, every time you play a video, it get's added to the playlist but never get's removed.

The proposal for the new behavior should be:

- Open With Audience should clear the previous queue and start playing that video. If multiple videos were selected, it will play the first form the selection and add the rest to the queue.

- Your queue will be saved and loaded if you opened the app and selected "Resume Last Video".

- You can still add files to the queue by using the Open File button from the popover, or by Drag and Dropping.

Whenever something is added to the queue, it needs some kind of feedback. In this case, the Playlist button's icon pulse blue for a a second or two