add a few more expresion examples to illustrate functions and -f 


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1641888 13f79535-47bb-0310-9956-ffa450edef68
xforms


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1641889 13f79535-47bb-0310-9956-ffa450edef68