Added configuration options for code completion

It is now possible to choose between case-sensitive or case-insensitive
completion. Also, you can now disable the automatic insertion of braces.

src/plugins/quickopen/settingspage.cpp

@@ -40,8 +40,6 @@
 #include <qtconcurrent/QtConcurrentTools>
 #include <utils/qtcassert.h>
 
-#include <QtGui/QMessageBox>
-
 Q_DECLARE_METATYPE(QuickOpen::IQuickOpenFilter*)
 
 using namespace QuickOpen;