Provide a socklen_t to the user of APR as a portability aid. Some

systems have unsigned sockaddr len parameters; others have signed.
When passing the length by address (as to accept()) a warning is
generated if the sign is not correct.

This patch assumes that, if no native socklen_t is provided,
apr_socklen_t is always signed; that can be easily tweaked for
certain platforms later.

Inside APR, apr_socklen_t is only used currently in the Unix
implementation.
Submitted by:	Victor J. Orlikowski <v.j.orlikowski@gte.net>
Reviewed by:	Jeff Trawick


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86282 13f79535-47bb-0310-9956-ffa450edef68