Browse Plex menus while video playback carries on

This might get even more relevant as Plex clients get DVR functionality (browse guide, recording schedules etc), but it would be nice in general if while watching a show I can go back and browse the menus and either the video shrinks and tucks itself in to a corner of the screen (audio still playing) or the video just goes away but audio can still be heard. Of course there should be a visual cue for the user to know what is playing and be able to navigate back to it.

2021 clean-up: implemented (minimizing the player will show a play-bar w/ with a mini-player at the bottom of the window while you’re able to navigate elsewhere)