Debugger: Fix std::string dumper on 64 bit

Task-number: QTCREATORBUG-10925
Change-Id: Iec57515e8adca8bd2e638157b9c1f0d4d9310c68
Reviewed-by: Christian Stenger <christian.stenger@digia.com>
Options Dialog: Prevent ghost widget

Change-Id: I06fc5820bffc47234b6b3b653b970ceac12640b1
Reviewed-by: Robert Loehning <robert.loehning@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>