Implementation of WB-649 (Restoring from Scenes Does Not Fully Restore Overlay...

Implementation of WB-649 (Restoring from Scenes Does Not Fully Restore Overlay ToolBox in Left Mode) is causing performance problems noticed when switching the selected tab.  Calling QComboBox::setSizeAdjustPolicy(QComboBox::AdjustToContents) appears to adjust the size of the combo box any time an item is inserted (found using Mac's Instruments Time Profiler) which is making updates very slow.  For now, the combo box size adjust policy has been changed to its default, QComboBox::AdjustToContentsOnFirstShow.