UPnP: Add MPEG_PS_PAL and MPEG_PS_NTSC to the list of supported DLNA protocols. Refs #12284
WebFrontend: More animation performance improvements, and other tweaking

Instead of animating through JS (jQuery), use native CSS3 transitions and
animations which are faster because they are handled in native code
and hardware accelerated. It's also the Right Way™ to do visual stuff
in web pages and makes it easier to tweak effects for different screen
sizes and platforms.