Fix ByFolder post-play navigation

Reference:
https://forums.plex.tv/index.php/topic/129936-menu-navigation-problems/
Do we really need this “volatile=*” everywhere?
Unplayed/partiallyPlayedDot is not shown in Grid view!
tweaks on aTV2 installation instructions
add short note on PILBackgrounds
hide/show search on shared list view
update latest git