included ethernet and arcnet in demo for readprop and server on Linux. Corrected the ethernet length. Corrected warnings in s_rp and s_whois.

bacnet-stack/demo/handler/s_rp.c

@@ -25,6 +25,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <errno.h>
+#include <string.h>
 #include "config.h"
 #include "config.h"
 #include "txbuf.h"

bacnet-stack/demo/handler/s_whois.c

@@ -25,6 +25,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <errno.h>
+#include <string.h>
 #include "config.h"
 #include "config.h"
 #include "txbuf.h"