Remove #include <extensionsystem/pluginmanager.h> from icore.h, a

forward declaration is sufficient.

src/plugins/cpptools/cppmodelmanager.cpp

@@ -51,6 +51,7 @@
 #include <coreplugin/editormanager/editormanager.h>
 #include <coreplugin/progressmanager/progressmanager.h>
 
+#include <extensionsystem/pluginmanager.h>
 #include <utils/qtcassert.h>
 
 #include <TranslationUnit.h>
@@ -69,8 +70,6 @@
 #include <QtCore/QMutexLocker>
 #include <QtCore/QTime>
 
-//#include <QtGui/QPlainTextEdit>
-
 using namespace CppTools;
 using namespace CppTools::Internal;
 using namespace CPlusPlus;