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.

moderators can override game restrictions and kick players when spectating; game host privileges shift when host leaves

fix: don't show conceded players, fix: compute multicolumn layout correctly when dealing with odd number of players