Support connection in any node.

mindplot/src/main/javascript/model/INodeModel.js

@@ -225,7 +225,7 @@ mindplot.model.INodeModel = new Class({
     deleteNode  : function() {
         var mindmap = this.getMindmap();
 
-        console.log(mindmap.inspect());
+        console.log("Before:" + mindmap.inspect());
         var parent = this.getParent();
         if ($defined(parent)) {
             parent.removeChild(this);
@@ -234,7 +234,7 @@ mindplot.model.INodeModel = new Class({
             mindmap.removeBranch(this);
         }
         // It's an isolated node. It must be a hole branch ...
-        console.log(mindmap.inspect());
+        console.log("After:" + mindmap.inspect());
     },
 
     getPropertiesKeys : function() {

mindplot/src/main/javascript/model/NodeModel.js

@@ -35,6 +35,10 @@ mindplot.model.NodeModel = new Class({
         this._notes = [];
     },
 
+    getPropertiesKeys : function() {
+        return Object.keys(this._properties);
+    },
+
     putProperty : function(key, value) {
         $defined(key, 'key can not be null');
         this._properties[key] = value;