DockLayout
Description:
Creates a new DockLayout.
 Instead of setting master directly with a master object, it is possible to use a 
      DockObject, in this case the layout will be attached to the same master than the dock
      object.
Parameters:
| master | 
           A master or a dock object to which the layout will be attached.  | 
      
Returns:
| 
           New DockLayout item.  |