vt71: Unable to extend Vtiger_Popup_Js
See my recent comments on the mailing list.
I can see no obvious way to extend the standard Popup.js class file.
The getHeaderScripts() method of the View class never seems to be loaded after the call in Vtiger_Basic_View.
I can hack the Basic view and add a $relatedModule from the $request object and load it that way but this not really ideal as it requires modifications to core code.