Header cleanup in various plugins.

Change-Id: I16b273cc792bfd2035d35e7c67675f039cd387b9
Reviewed-on: http://codereview.qt.nokia.com/3185
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>

src/plugins/cpptools/abstracteditorsupport.h

@@ -35,7 +35,11 @@
 
 #include "cpptools_global.h"
 
-#include <cplusplus/ModelManagerInterface.h>
+#include <QtCore/QString>
+
+namespace CPlusPlus {
+class CppModelManagerInterface;
+}
 
 namespace CppTools {