feature: new constructor SpoonModelTree(CtElement)

src/main/java/spoon/support/gui/SpoonModelTree.java

@@ -45,6 +45,7 @@
 import javax.swing.tree.TreePath;
 
 import spoon.Launcher;
+import spoon.reflect.declaration.CtElement;
 import spoon.reflect.factory.Factory;
 import spoon.support.SerializationModelStreamer;
 
@@ -81,6 +82,15 @@ public SpoonModelTree(Factory factory) {
 		initialize();
 	}
 
+	public SpoonModelTree(CtElement rootElement) {
+		super();
+		SpoonTreeBuilder cst = new SpoonTreeBuilder();
+		cst.scan(rootElement);
+		this.factory = rootElement.getFactory();
+		root = cst.getRoot();
+		initialize();
+	}
+
 	/**
 	 * This method initializes jContentPane
 	 *