multiple backported fixes
    
    - add inactive account lock out functionality to pam_lastlog
    - fix pam_unix remember user name matching
    - add gecoscheck and maxclassrepeat functionality to pam_cracklib
    - correctly check for crypt() returning NULL in pam_unix
    - pam_unix - do not fallback to MD5 on password change
      if requested algorithm not supported by crypt() (#818741)