Relevant BUGIDs: Red Hat bz 171164

Relevant BUGIDs: Red Hat bz 171164

Purpose of commit: new feature

Commit summary:
---------------
2005-10-20  Tomas Mraz  <t8m@centrum.cz>

        * configure.in: Added check for xauth binary and --with-xauth option.
        * config.h.in: Added configurable PAM_PATH_XAUTH.
        * modules/pam_xauth/README,
        modules/pam_xauth/pam_xauth.8: Document where xauth is looked for.
        * modules/pam_xauth/pam_xauth.c (pam_sm_open_session): Implement
        searching xauth binary on multiple places.
        (run_coprocess): Don't use execvp as it can be a security risk.