Simple support for Constraints in the Wall Builder random map library, so that one can place walls while avoiding collisions, refs #5003.
Return the placed entities, so that one can parse and elegantly avoid them afterwards, in particular determine gate positions.
placeCircularWall uses the startAngle as orientation, since that is much easier to pass than the opposite vector of the center of the wall.
git-svn-id: https://svn.wildfiregames.com/public/ps/trunk@21554 3db68df2-c116-0410-a063-a993310a9797