Invites and the generate invite form are now displayed as cards. Invite
codes are displayed in a monospace font so they are always aligned with
eachother. The delete button is now inline with the rest of the text.
Fixed an issue where some criteria on the form page wouldn't change to
red or green when one set one of them to 0 in the config. Also added a
lowercase option.
Password validation added, configurable under the [password_validation]
section in config.ini. Each criterion is displayed next to the form, in
red or green depending on whether the password passes it. form.html now
looks different because of it, whether it is enabled or disabled. An
error message is now displayed if the user already exists.
Changed admin.js so that instead of deleting all invites and then
generating them, new ones are created, pre-existing ones have their
expiry updated, and newly invalid ones are deleted. Accidentally
improved their layout, as well.