Make do_rfc1413 a per-directory core configuration variable.

Replace all accesses to the connection.remote_logname
variables to calls to get_remote_logname(). Rewrite rfc931.c as
rfc1413.c to conform to new standard, avoid stdio and avoid syslog.

Submitted by: drtr@ast.cam.ac.uk (David Robinson)
Obtained from: 112b.ident.patch


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@76335 13f79535-47bb-0310-9956-ffa450edef68