Introduced a mechanism to load required javascripts at runtime

(lazy loading) using the require.js. This allows us to load the
javascript required for any node, only when it was loaded in the browser
tree. Also, introduced the mechanism to show/edit/create of any node in
a tab panel (wcDocker.Panel).

web/pgadmin/utils/menu.py

@@ -1,3 +1,12 @@
+##########################################################################
+#
+# pgAdmin 4 - PostgreSQL Tools
+#
+# Copyright (C) 2013 - 2015, The pgAdmin Development Team
+# This software is released under the PostgreSQL Licence
+#
+##########################################################################
+
 from collections import namedtuple
 
 PRIORITY = 100
@@ -10,16 +19,19 @@ class MenuItem(object):
 class Panel(object):
 
     def __init__(self, name, title, content, width=500, height=600, isIframe=True,
-                 showTitle=True, isCloseable=True, isPrivate=False, priority=None):
+                 showTitle=True, isCloseable=True, isPrivate=False, priority=None,
+                 icon=None, data=None):
         self.name = name
         self.title = title
         self.content = content
         self.width = width
         self.height = height
-        self.isIfframe = isIframe
+        self.isIframe = isIframe
         self.showTitle = showTitle
         self.isCloseable = isCloseable
         self.isPrivate = isPrivate
+        self.icon = icon
+        self.data = None
         if priority is None:
             global PRIORITY
             PRIORITY += 100