Major cleanup:

Major cleanup:

  - add __unused where appropriate
  - PAM_RETURN -> return since OpenPAM already logs the return value.
  - make PAM_LOG use openpam_log()
  - make PAM_VERBOSE_ERROR use openpam_get_option() and check flags
    for PAM_SILENT
  - remove dummy functions since OpenPAM handles missing service
    functions
  - fix various warnings

Sponsored by:	DARPA, NAI Labs