[imp] imp CVS, hordeauth / auto login and secure request token checker thing

[Liam Hoekenga]

I installed HEAD.  We use a custom auth handler, and have hordeauth set to 
true in imp/servers.php

We're entering the application through https://mail.example.edu/horde/, 
and now we're getting..

"It cannot be verified that this request was really sent by you. It could 
be a potentially malicious request."

How do we fix this?  How do we provide required tokens to let us in, or 
how do we turn this off?

Liam