Update XForm title when form name is changed

Addresses this [ticket](http://manage.dimagi.com/default.asp?141586).
Only the form builder was updating the name of a form in the XForm. Therefore, if a user changed the name of a form and deployed without first saving in the form builder again, the XForm would not be updated. this resulted in the "You are at the start of `<form name>` ..." and "You are at the end of `<form name>` ..." messages on the mobile device to display the wrong form name.

I've changed the method that alters the form name to also alter the name on the XForm, thereby resolving the issue.
Could use `xform.render()`