This has nothing to do with CAPTCHA generation, and the only thing it
needs from the SimpleCaptcha class is checking whether a CAPTCHA on
bad login is enabled at all.
Also improve comments in CaptchaPreAuthenticationProvider. I found the
session flag business really difficult to understand.
Change-Id: I8200531718aaa11effcb07539204e1a05ed432e0
Changes to the use statements done automatically via script
Addition of missing use statements done manually
Change-Id: Id44f211320e56bc83e4c8f243369dc4eb562cf37
isBadLoginPerUserTriggered() can never return null. This comment was
added in 2016 in 31c59374a4 and it was
already incorrect then. I don't know where this idea came from.
Change-Id: Ib919999fe83562cb4fa80246ae7c6b4707da775c
