cleanups: unnecessary casts, unified const_1, eliminate cross-.c file

prototypes (heresy!), add spaces in places like "flags&NETSTAT_CONNECTED",
removed unused #defines, #ifdef -> #if, use uint32_t for ipv4 addrs.

libbb/messages.c

@@ -40,6 +40,9 @@ const char bb_path_motd_file[] = "/etc/motd";
 const char bb_default_login_shell[] = LIBBB_DEFAULT_LOGIN_SHELL;
 const char bb_dev_null[] = "/dev/null";
 
+const int const_int_0;
+const int const_int_1 = 1;
+
 #include <utmp.h>
 /* This is usually something like "/var/adm/wtmp" or "/var/log/wtmp" */
 const char bb_path_wtmp_file[] =