Slot Viewer Review1: (1.2) Opening a slot already in the Viewer should just select that slot.
Bug Number: n/a
Release notes (y/n): no
For Release Nums: 7.2

See Review1 Notes:
  http://cadswes2.colorado.edu/~philw/2017/SlotViewer/Review1/

1.2: Opening a slot that is already shown in the viewer re-orders the 
columns to put that one on the right. It should just open the viewer 
and select that column without re-ordering.

Also, in the course of selecting the added slots, for no good reason, 
the top-left visible cell was always becoming the new Current Cell.  
This has been changed to always set the current cell to one in the 
newly selected display columns.