Exempt or Include Buildings when Mass-Selecting

Buildings that undeploy are included in the mass selection (holding left mouse button, dragging a rectangle). This might be unwanted for buildings that are not to be considered deployed units even if they can undeploy.

[BuildingType]MassSelectable= (boolean, defaults to yes for 1x1 buildings with UndeploysInto= set)
Whether buildings of this type are considered units when mass-selecting. If no, buildings will not be included in the selection, even if they undeploy into a unit and are actually to be considered vehicles.