manual test case for running transformerHook on form post response.

following up on the mailing list thread:

https://groups.google.com/forum/#!topic/obviel/5pE2fU-sEoQ

I have written a counter-example.  It even includes a (probably stupid, but hopefully still helpful) suggestion how to fix it, readable when you run the example.

please let me know if you want me to change anything before you can pull.

thanks,
cheers,
matthias