Improved API

The API keys page leads with your keys

The create form stays closed until you ask for it, and each key shows when it was created and last used.

The API keys page now opens on the keys you already have instead of an empty create form. Create key in the page bar opens the form, so a stray submit cannot make a key you did not ask for. Each key is listed with the characters it starts with, when it was created, when it was last used, and a Revoke button beside it. A new key is still shown once, immediately after it is created, and cannot be shown again.