Update the internal variable that aids rotation

Update the THEN variable that is used in the spin function to determine
the new angle of rotation.
Add a param to the rotational adjustment methods
Adjusting the point radius of the marker
Allow marker size to be defined as a percentage
Added control for marker animation duration
Bug fix in marker animation
Cleaning up parameters/variables
Add ability to uncouple the table descriptor
Pausing rotation as soon as mouse is down
Adding padding to the right side
Fix minor bug in dragging action

The dragging shifts to 0° 0' 0" E  0° 0' 0" N - we need to keep the
current location in sight.