Fixed bug that causes hang on close sidebyside window

If you open two procedures and then drag one of them so that it is next to the other and then close one of the two procedures, PROMS2010 would hang.

PROMS/Volian.Controls.Library/DisplayTabControl.cs

@@ -287,6 +287,7 @@ namespace Volian.Controls.Library
 				if (myBar.DockSide == eDockSide.Document && myBar.Visible)
 				{
 					ActivateRemainingTab(myBar);
+					return;
 				}
 			}
 			// No Document Tabs Remaining - need to raise OnItemSelectedChanged