Proposed enhancement for pam_krb5: "optional_ccache"

Hello!

  I'd like to propose an enhancement for pam_krb5: a new option 
"optional_ccache", which allows pam_krb5 not to fail in pam_sm_setcred 
when pam_sm_authenticate hasn't obtained credentials. The patch and 
detailed descriptions are available in PR 91954 
(http://www.freebsd.org/cgi/query-pr.cgi?pr=91954)

  Comments are welcome, but please keep my e-mail on CC line as I'm not on 
the list. If this enhancement is acceptable I'd happy if someone commits 
it.

-- 
Oleg Sharoiko.
Software and Network Engineer
Computer Center of Rostov State University.