Slot Dialog (and related apps): Phantom column remains when column removed [5856/5884]
Bug Number:  5856 and 5884
Release notes (y/n): Yes
For Release Nums: 7.0.2 and 7.1

5856: Open Table Slot Dialog: column deletion operations create a phantom GUI column.
5884: Object Account Summary has phantom columns when accounts are removed from the list.

In certain transitions, the SCT data column header widths (horizontal 
QHeaderView on the data table) were not being assigned the proper 
attributes.  This _seems_ to be some buggy behavior in Qt 5.5.1's 
QHeaderView class -- see this unanswered question on the Qt Forum, 
and our related bug: 5856.

  Can't hide QTableView column after 'resetting' the QAbstractTableModel
  https://forum.qt.io/topic/74052

We were unable to fix this without deleting and recreating the data 
table's horizontal QHeaderView.  See new method: void SlotDataTableView::
recreateHorizontalHeaderView().