clean up "Add" menubar categoes on the 3d object side via the following:

SceneObject now defaults to a category of "misc"
getCategoryOfClass now checks parent classes for what categories they hold so that variants can inherit
categories are in one of a few rough groups and subgroups depending on actual mapper needs/usages

Engine/source/T3D/vehicles/flyingVehicle.h

@@ -180,6 +180,7 @@ class FlyingVehicle: public Vehicle
    U32 getCollisionMask();
   public:
    DECLARE_CONOBJECT(FlyingVehicle);
+   DECLARE_CATEGORY("Actor \t Controllable");
    static void initPersistFields();
 
    FlyingVehicle();

Engine/source/T3D/vehicles/hoverVehicle.h

@@ -200,6 +200,7 @@ class HoverVehicle : public Vehicle
    void advanceTime(F32 dt);
 
    DECLARE_CONOBJECT(HoverVehicle);
+   DECLARE_CATEGORY("Actor \t Controllable");
 //   static void initPersistFields();
 
    U32  packUpdate  (NetConnection *conn, U32 mask, BitStream *stream);

Engine/source/T3D/vehicles/vehicle.h

@@ -165,6 +165,7 @@ public:
    /// @}
 
    DECLARE_CONOBJECT(Vehicle);
+   DECLARE_CATEGORY("UNLISTED");
 };
 
 

Engine/source/T3D/vehicles/vehicleBlocker.h

@@ -52,6 +52,7 @@ class VehicleBlocker : public SceneObject
    ~VehicleBlocker();
 
    DECLARE_CONOBJECT(VehicleBlocker);
+   DECLARE_CATEGORY("Area");
    static void initPersistFields();
 
    U32  packUpdate  (NetConnection *conn, U32 mask, BitStream *stream);

Engine/source/T3D/vehicles/wheeledVehicle.h

@@ -225,6 +225,7 @@ class WheeledVehicle: public Vehicle
 
 public:
    DECLARE_CONOBJECT(WheeledVehicle);
+   DECLARE_CATEGORY("Actor \t Controllable");
    static void initPersistFields();
 
    WheeledVehicle();