Add new scene controller with touch display example.

Upgraded RF24 to latest version which supports SoftSPI. 
Added DigitalIO and UTFT libraries to support the new example.
Fix problem reported in RelayWithButtonActuator example.

libraries/UIPEthernet/utility/util.h

@@ -0,0 +1,13 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#define htons(x) ( ((x)<<8) | (((x)>>8)&0xFF) )
+#define ntohs(x) htons(x)
+
+#define htonl(x) ( ((x)<<24 & 0xFF000000UL) | \
+                   ((x)<< 8 & 0x00FF0000UL) | \
+                   ((x)>> 8 & 0x0000FF00UL) | \
+                   ((x)>>24 & 0x000000FFUL) )
+#define ntohl(x) htonl(x)
+
+#endif