Refactor Formo::add_before/after_submit() functions a bit.  Same net results.
Update Formo - include a new improvement on set_fields() and set_var_fields().
Revise Controller_Items to use new Formo improvement.
Remove unneeded CSS class in login/reauth - g-narrow has been gone for awhile...
Move login form CSS from user module to gallery module.
Add "show_in_dialog" argument to dialog JSON, which makes the dialog stay open.
This is useful for ajax redirection, e.g. login/reauthenticate redirection
before an ajax dialog (login in two windows, logout in one, then click
"edit album" in the other - the ajax login should pop up and, on completion,
reload with the Edit Album dialog.)
Use new "show_in_dialog" argument to make login/reauth before an ajax dialog
work really well.
Fix big with Controller_Items::get_form_labels().  Oops.
Refactor logout controller a bit to look more like login/reauth.
Make Controller_Admin an abstract class - it should never be executed directly.
Revise comments in Response to reflect "show_in_dialog" changes.
Make some internal Auth callback functions protected for better security.
Reformat the Auth class - reorder the functions (no functional changes).