[Catalyst] Handling add/edit screens

[moltar]

This is a very common scenario. First you have a form to add a record, 
and then later you want to edit the record. Sometimes the records is 
*almost* the same, but not quite.

For example, editing a user profile - users must provide a username when 
registering, but can't change it on the edit screen. Also while editing 
user profile, they must provide an old password and a new one twice. But 
the rest of the form (name, email, address, etc...) is exactly the same.

What are the best methods for handling these kinds of forms? What 
concerns me most is the code/template repetition.

I am using FormValidator::Simple.