User Form/Display (Complete), Bugfixes

User modify form and view page are finished now.  All elements, all
JavaScript notifications.

Fixed a bug that would allow users with a correct username and password,
but disabled account to login.

Expanded API error handling -- even errors caused by thrown exceptions
in the API code will use the lightweight API error handling now.

Added a new helper method to the User class which will allow the setting
of arbitrary session keys to users, this will be used when/if we
implement cross-site session propagation for seamless integration with
the MISA Wordpress site.