Move NearestWalkableTileOf() function from World to Path
Path: NearestWalkableTileOf() uses priority_queue
Renderer: Fullscreen mode isn't the default mode in Release anymore
Fixe: Move order uses hostUnit as source position for NearestWalkableTileOf()
World: Move the initial townhall position
Path: Little hack in NearestWalkableTileOf() makes it look better (acceptable is the word)