[auth1.c auth2.c auth2-pubkey.c auth.h auth-krb5.c auth-passwd.c]
[auth-rhosts.c auth-rh-rsa.c auth-rsa.c monitor.c serverloop.c]
[session.c]
standardise arguments to auth methods - they should all take authctxt.
check authctxt->valid rather then pw != NULL; ok markus@
[auth.h auth2.c auth2-hostbased.c auth2-kbdint.c auth2-none.c
auth2-passwd.c auth2-pubkey.c Makefile.in]
split auth2.c into one file per method; ok provos@/deraadt@
NOTE: Merged back noticable cygwin and pam stuff. May need review to
ensure I did not miss anything.