This is the first implementation of a theme manager. It’s a rebased and
revisited version of #792.

Updated default colors, darker, more modern, slick. Great feedback from
community.

Set to false by default, let me know if you think it should be true.

As all cards are played to the left of the screen this feels more
comfortable to use as you dont need to keep looking at different areas
of the screen.

Will auto rearrange when changed during game-play.

+ Added a fade to inactive players TableZone
+ Refreshed TableZone, HandZone and DeckView  default background colors

Revealing a library to a player now grants that player permission to drag cards out of that library onto his own table. This permission is revoked by shuffling the library. The zone view window tracks content changes of the zone for as long as the permission lasts so that card ID changes are kept track of. This hopefully fixes issues #5 and #12.