Slot Viewer: (1) Exclude multiple-column AggSeries, (2) File menu Dock/Undock ops
Bug Number: n/a
Release notes (y/n): no
For Release Nums: 7.2

Slot Viewer finishing tasks.  This is now provisionally finished.

  (1) Multiple column AggSeriesSlots will be shown in ONLY their Open Slot 
      Dialog, and not the Slot Viewer.  When a single-column AggSeriesSlot 
      becomes multiple-column, it is removed from the Slot Viewer.
     
  (2) Added "File" menu operations:

    In Slot Viewer: Undock Slot...
    In Slot Viewer: Undock All Slots...  (this also closes the Slot Viewer).
    In Slot Dialog:  Dock in Slot Viewer...  (only for supported slots).

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