Add include files to get prototype declarations, and fix bugs found.

Add include files to get prototype declarations, and fix bugs found.

SCCS-vsn: lib/libc/net/gethostnamadr.c 6.43
SCCS-vsn: lib/libc/net/getnetbyname.c 5.7
SCCS-vsn: lib/libc/net/getnetent.c 5.8
SCCS-vsn: lib/libc/net/getprotoent.c 5.8
SCCS-vsn: lib/libc/net/getprotoname.c 5.7
SCCS-vsn: lib/libc/net/getservbyname.c 5.7
SCCS-vsn: lib/libc/net/getservbyport.c 5.7
SCCS-vsn: lib/libc/net/getservent.c 5.9
SCCS-vsn: lib/libc/net/herror.c 6.6
SCCS-vsn: lib/libc/net/inet_addr.c 5.9
SCCS-vsn: lib/libc/net/inet_lnaof.c 5.7
SCCS-vsn: lib/libc/net/inet_makeaddr.c 5.6
SCCS-vsn: lib/libc/net/inet_netof.c 5.7
SCCS-vsn: lib/libc/net/inet_network.c 5.7
SCCS-vsn: lib/libc/net/inet_ntoa.c 5.6
SCCS-vsn: lib/libc/net/iso_addr.c 5.4
SCCS-vsn: lib/libc/net/linkaddr.c 5.2
SCCS-vsn: lib/libc/net/ns_addr.c 6.7
SCCS-vsn: lib/libc/net/ns_ntoa.c 6.6
SCCS-vsn: lib/libc/net/rcmd.c 5.23
SCCS-vsn: lib/libc/net/recv.c 5.3
SCCS-vsn: lib/libc/net/res_comp.c 6.20
SCCS-vsn: lib/libc/net/res_debug.c 5.33
SCCS-vsn: lib/libc/net/res_init.c 6.15
SCCS-vsn: lib/libc/net/res_mkquery.c 6.15
SCCS-vsn: lib/libc/net/res_query.c 5.9
SCCS-vsn: lib/libc/net/res_send.c 6.27
SCCS-vsn: lib/libc/net/send.c 5.3
SCCS-vsn: lib/libc/net/sethostent.c 6.8