Store messages by mood so they can be grouped up
change default mood to positive and add a default colour to catch messages with a wrong mood
migrate settings so upgrading vs new is consistent
add new methods to messages class to let it take care of stash and pop of the messages
update login.php to use new methods
tweak html function to put the $_SESSION['message'] in the stack so there is only one code point to maintain for rendering
Implement new messages class
Support legacy $_SESSION['message_*']
New function messages::add($message, $mood, $delay) to simplify adding messages
updated core/users/user_edit.php to demonstrate
includes space->tab corrections