Refactored some of the returnto handling code. It looks like we have several different ways of handling this in the software, icky!
Marked the session-based functions with fixmes (they'll stomp on other forms when multiple tabs/windows are used) and combined some commonish bits of code between ProfileFormAction and the group block & makeadmin actions where they're using hidden form parameters. Extended that to allow passing dynamic parameters (eg 'page') as well as static ones (action, target user/group).
Setting focus into the form to make it easier to submit by keyboard. Enter or space will now trigger the button right off without having to mouse around to find the button after we've clicked into the conf form, and keyboarders can also get to the 'no' button more easily.
