qmljs: split scan function

allows to more easily scan the various qml dialects

Change-Id: I9f8c44459e05e4658d3814c624e0f07762c83279
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>

src/libs/qmljs/qmljsmodelmanagerinterface.h

@@ -244,6 +244,7 @@ protected:
                                   CPlusPlus::Snapshot snapshot,
                                   QHash<QString, QPair<CPlusPlus::Document::Ptr, bool> > documents);
 
+    void maybeScan(const QStringList &importPaths, Language::Enum defaultLanguage);
     void updateImportPaths();
     void loadQmlTypeDescriptionsInternal(const QString &path);