Browsers try very hard these days to be helpful by capturing data

entered into username/password fields and auto-filling them. While

generally useful, this ends up being a problem for settings forms that

are trying to configure other services or users.
There's no officially-supported way to disable these, and browsers try

to be smart by checking for password field types and certain labels, but

a trick that works pretty well (and ahs been used by other projects) is

to place a hidden password input without a name attribute at the top of

the form. The browser will see this, auto-fill it, and ignore any

subsequent username/password field combinations.
This change applies this to all admin settings forms and the repository

change form.

Tested in Chrome, Safari, and Firefox. Prior to this change, I could make

Chrome and Firefox auto-fill username/passwords for repository hosting

service information and for e-mail configuration. After this change, they

wouldn't auto-fill at all anymore.
Safari's behavior in this area is quite different. I still get the option

to auto-fill, but it doesn't force it. This behavior is the same both before

and after this fix. However, older versions behaved like Chrome and Firefox,

so my hope is that those will be fixed.