graph_editor: move springy in dream_graph_editor/lib

External dependencies are there

bt5/erp5_graph_editor/SkinTemplateItem/portal_skins/erp5_graph_editor/dream_graph_editor/jsplumb/index.html.html

@@ -13,9 +13,9 @@
     <script src="../lib/jquery-ui.js"  type="text/javascript"></script>
     <script src="../lib/jquery.jsplumb.js" type="text/javascript"></script>
     <script src="../lib/handlebars.min.js" type="text/javascript"></script>
+    <script src="../lib/springy.js" type="text/javascript"></script>
 
     <script src="../dream/mixin_promise.js" type="text/javascript"></script>
-    <script src="springy.js" type="text/javascript"></script>
     <script src="jsplumb.js" type="text/javascript"></script>
 
     <script id="node-template" type="text/x-handlebars-template">