Select3D_SensitiveCircle now inherits directly from Select3D_SensitiveEntity.
The sensitive circle sector is created using the Select3D_SensitivePoly class directly.
Added appropriate methods for selecting sensitive circles.
Added parameter myIsHollow to Select3D_SensitiveCylinder class.
It allows you to search for intersections with cylinders without covers.
The Draw vcircle command has been extended with UStart and UEnd parameters
to create a sector of a circle.
Added tests: vselect/cone_cylinder/circle_sector
vselect/cone_cylinder/circle_wire
vselect/cone_cylinder/filled_circle
vselect/cone_cylinder/transformed
vselect/cone_cylinder/hollow_cone_cyl
