Add Cancel buttons to Password & Admin actions

Closes #56

Add Cancel buttons to Set/Reset/Change Password screens, and to
Release Lock, Check Table Setting Syntax, and other Admin screens.
Move all submit buttons from Zend Forms to Controllers for better
integration with Twitter Bootstrap (esp. Save and Cancel buttons).
Clean up scripts for many basic screens to use a single general-purpose
helper, improve error and message handling on those screens.

Improve Release Locks to show users who have locks and then, once a user
has been chosen, show what locks that user has.  Reduces need to view
Locks table before releasing a lock.

Create a new Form class from which other forms can inherit a
createHiddenElement function that does a better job of hiding elements,
their labels, and their error messages.