Simply extends Jenkins' simple security to remove the CAPTCHA check.
Probably should deprecate this plugin and roll into the core security, but I didn't want to try and touch the core since it's "security".
If this can't be rolled into the core security, then at least the core should be tweaked to be more extensible - e.g. make about 5 methods protected instead of private. The problem with that is then this plugin would depend on the very latest core, which is okay since Jenkins warns you not to upgrade.