Update pam_pwhistory to use pwhistory.conf

With libpam 1.5.3, pam_pwhistory added support to get configuration
options from pwhistory.conf similar to faillock and pwquality.

This updates pam_pwhistory to use pwhistory.conf for the remember
setting.

pwhistory remember was the last setting directly using the
common-password file, so this also removes the two functions to get and
set PAM module arg values which resolves #16.

Tested:
Confirmed that getting and setting the RememberOldPasswordTimes D-Bus
property gets and sets the remember value in pwhistory.conf.

Change-Id: If8f90720c120c5c49e2b8b4a840a427d46ffc7d9
Signed-off-by: Jason M. Bills <jason.m.bills@intel.com>
3 files changed