Move C++ mime types from cppeditor to cpptools

Have the mimetypes and their registration in the same plugin
as their constants.

Change-Id: I350ab4eb0da3941ca9282ff98d8d0e158b568ef3
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/cppeditor/cppeditorplugin.cpp

@@ -141,7 +141,6 @@ CppQuickFixAssistProvider *CppEditorPlugin::quickFixProvider() const
 bool CppEditorPlugin::initialize(const QStringList & /*arguments*/, QString *errorMessage)
 {
     Q_UNUSED(errorMessage)
-    Utils::MimeDatabase::addMimeTypes(QLatin1String(":/cppeditor/CppEditor.mimetypes.xml"));
 
     addAutoReleasedObject(new CppEditorFactory);
     addAutoReleasedObject(new CppOutlineWidgetFactory);