[trac import 10/16/14 by nuwan] Reference element must be text

[devinbalkind]

Firstly, the element in both the Create/Edit? CAP Template and Create/Edit? CAP message is a drop-down object. It should be changed to a text box-control object.
Secondly, the logic to fill the text-box should be implemented. It is an optional field. However, we should implement the logic to automatically fill it. If the implementation does not want that, then the it easy to simply comment out the code.
Here's the logic
The group listing identifying earlier message(s) referenced by the alert message (OPTIONAL)
(1) The extended message identifier(s) (in the form sender,identifier,sent) of an earlier CAP message or messages referenced by this one.
(2) If multiple messages are referenced, they SHALL be separated by whitespace.
Here's what you should do
If the text-box is empty (or NULL), then when the On-Save, fill it with the values already available in the and elements. An alternative is to fill the element On-lost-focus or when the elements are completed.