Modified pre-processing logic for panel-urls

Look at the active tab only for how to fill the various placeholders
No need to go upto the .g-panel
 Removed alert
Changed key :who to :user in the returned JSON

We were using :user in another request for the same reason - distinguishing
b/w teachers and students. As here too the key was being used for the
same purpose, it should have the same name

In fact, :name, :id and :user should be standardized key names across the app