More portability changes, and some bugfixes found through that.

src/network/slirp/slirp.h

@@ -64,6 +64,7 @@ typedef unsigned long 	ioctlsockopt_t;
 # define HAVE_STDLIB_H
 # define HAVE_STRING_H
 # define HAVE_UNISTD_H
+# define HAVE_INET_ATON
 typedef uint8_t u_int8_t;
 typedef uint16_t u_int16_t;
 typedef uint32_t u_int32_t;