Reworking management of Slot Dialogs, no longer via Open Object Dialogs [2]
Bug Number: n/a
Release notes (y/n): no
For Release Nums: 7.2

Removal of the the GUI/SlotDialogManager class.  This was part of the 
no-longer-used application level Parent Dialog / Child Dialog relationship 
mechanism between Open Object Dialogs and Open Slot Dialogs.

A couple methods which are still required were moved to the Workspace class, 
operating off of the Workspaces new Slot Dialog collection:

  static QMap<Slot*, QMainWindow*> Workspace::_openSlotDlgMap;

  static void updateSlotDialogs (bool appFontChanged=false);
  static void closeSlotDlgsForSimObj (SimObj*);

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