Include <ctype.h> for the tolower macro/function.  Add an explicit
return type void for log_bind_result.  This avoids build failures with
future compilers which do not support implicit function declarations
or implicit ints.

Submitted upstream: <https://sourceforge.net/p/inadyn-mt/patches/54/>

diff --git a/src/ip.c b/src/ip.c
index 2c5876d7f8ceef6e..3bf836b37bf95535 100644
--- a/src/ip.c
+++ b/src/ip.c
@@ -41,6 +41,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #include "os.h"
 #endif
 
+#include <ctype.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
@@ -863,7 +864,7 @@ static int do_do_if_bind(struct sockaddr_storage *p_bind_in,SOCKET socket,struct
 	return bind_ret;
 }
 
-static log_bind_result(int bind_ret,char *if_name,char *s_binded_addr)
+static void log_bind_result(int bind_ret,char *if_name,char *s_binded_addr)
 {
 
 	if (0==bind_ret) {