Made coordinate explicit not null, fixes waning that goog.math.Coordinate.sum requires non null parameters.
Made coordinate explicit not null, fixes waning that goog.math.Coordinate.sum requires non null parameters.

digitalfruit/limejs,wikieswan/limejs,oleg-kipling/limejs,runawaygo/Saver2012,Diaosir/limejs,sjamog/Lime-Projects,digitalfruit/limejs,srbala/limejs,Diaosir/limejs,squallyan/limejs,digitalfruit/limejs,ZzCalvinzZ/ludumdare26,saulpw/nucleotron,srbala/limejs,srbala/limejs,wikieswan/limejs,oleg-kipling/limejs,squallyan/limejs,ZzCalvinzZ/ludumdare26,Inframatic/theBasics,GeorgeMe/limejs,GeorgeMe/limejs,GeorgeMe/limejs,oleg-kipling/limejs,sjamog/Lime-Projects,saulpw/nucleotron,Diaosir/limejs,runawaygo/Saver2012,Inframatic/theBasics,squallyan/limejs,sjamog/Lime-Projects,wikieswan/limejs