[cgiapp] simple example of CA, jQuery, Ajax added to wiki

[Mark Rajcok]

I had on my todo list (for over a year) to add to the CA wiki a simple
example of using jQuery to make Ajax requests back to the server using a CA
backend.  I finally wrote the 62 lines of code:
  http://cgiapp.erlbaum.net/index.cgi?AjaxInfo