QmlJS: Add 'reformat' action which regenerates the whole file.

Change-Id: I0aed6c6e197e122200d720eb9291a083095a6299
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>

src/plugins/qmljseditor/qmljseditor.h

@@ -182,6 +182,7 @@ public slots:
 signals:
     void outlineModelIndexChanged(const QModelIndex &index);
     void selectedElementsChanged(QList<int> offsets, const QString &wordAtCursor);
+    void semanticInfoUpdated();
 
 private slots:
     void onDocumentUpdated(QmlJS::Document::Ptr doc);