Changed sha1 into bcrypt continued...

| Q   | A
| --- | ---
| Doc fix? | yes
| New docs? | no
| Applies to | 2.2+ (bcrypt was introduced in 2.2)
| Fixed tickets | https://twitter.com/ircmaxell/status/412978651123023872

This follows @WouterJ's start in #3356. It uses BCrypt in even more places and reorganizes some sections. Hopefully this puts us in a good place. Comments warmly appreciated!

Thanks!