* fixed force video
* improved handling of switch between force video and audio only
	* force video persists with the media, audio only (in a prefer-video feed) applies when current media is not changed
* in PlayerDetailed
	* replaced external media panel with "Change stream" in the menu, shown only on applicable media
	* added StreamChanger popup, where if applicable, one can change locale, codec and biterate for audio, and video codec and resolution for video
