Add checks to prevent former passwords from being reused
Make number of banned former passwords configurable

Also group settings into fieldsets on the authentication settings page.
Update TestUnit fixtures with UserPasswords
Fix old migration salting existing user passwords
Fix syntax for salt user passwords migration
Add migration for creating user passwords
Fix new user password not being immediately used
Add cuke for ban of former passwords
Fix admin info showing whether admin password was changed
Remove test for removed salting unsalted passwords
Fix password check for user without password and fix tests
Fix password complexity feature after translation changes