_gtkAdjustementNew
_gtkAdjustementNew creates a new Adjustments object.
It is created with this default setting :
- value : 0;
- lower : 0;
- upper : 100;
- step increment : 2;
- page increment : 10;
- page-size : 20.
Prototype : fun [Chn] ObjGtkAdjustment
- Chn : the owner channel
- Return ObjGtkAdjustment : the new object or nil if an error occurs.