New doctrine listener for dynamic mappings and a bunch of other stuff.
This reverts commit 80be9ae. Zend\Session\Container has some bugs with tracking hops that need addressed first. FlashMessenger is unaffected because it unsets messages as they're accessed.
Also removed salt from login form for now. There's not much CSRF danger on a login form since the password is required, plus it makes setting up a custom login form annoying.