[VEX] point-vertex, Add these value in VEX.

------- point 
int  addpoint(int geohandle, int point_number)
int  addpoint(int geohandle, vector pos)
 
ex). v@cent = addpoint(0,centp);

------- vertex
int  addvertex(int geohandle, int prim_num, int point_num)

ex).