Extension: RTS-like unit selection

How To Use: - The "Allow player to Select units" action must run every frame to work properly - When a drag is in progress, all units inside the selection box will be "PreSelected" - When the drag is released, all "PreSelected" units will be changed to "Selected" - Hold the additive select key to add units to selection - Hold the subtractive select key to remove units from selection Control Group controls: - Ctrl + (1,2,3,4,5,6,7,9,0) assigns that Control Group to Selected units - (1,2,3,4,5,6,7...