VERSION: Increment to 11.27
CHANGE: Improve performance when route-finding for many ships at once (TurfIt)
CHANGE: Increase range before route-finding for ships gives up entirely (TurfIt)
FIX: Crash on loading in some cases (ultimate cause unknown).
CHANGE: Reduce the maximum number of ships on a tile to prevent ship overflows (as recommended by TurfIt)
CHANGE: Optimise fix for loading errors.