Remove vestigial _USE_TIRPC_IPV6 preprocessor conditional.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>
Update newxprt->lt_addr on accept (svc_vc)

Signed-off-by: Matt Benjamin <matt@linuxbox.com>
Add svc_getlocal_netbuf.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>
Client handle cardinality (svc_vc).

In order to support multiple client sessions on a single
connection, permit a caller to create additional client handles,
moving serialized call data (e.g., program number) into a
new ct_serialized structure.  This is linked from a new cl_p3
private member.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>