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/UTFT/hardware/avr/HW_AVR_defines.h

@@ -0,0 +1,25 @@
+// Enable or disable the use of a display shield designed for use on 
+// an Arduino Uno (or compatible) on an Arduino Mega
+//
+// ** Currently only available for 8bit display shields **
+//
+// Uncomment the following line to enable this feature
+//#define USE_UNO_SHIELD_ON_MEGA 1
+//********************************************************************
+
+// *** Hardwarespecific defines ***
+#define cbi(reg, bitmask) *reg &= ~bitmask
+#define sbi(reg, bitmask) *reg |= bitmask
+#define pulse_high(reg, bitmask) sbi(reg, bitmask); cbi(reg, bitmask);
+#define pulse_low(reg, bitmask) cbi(reg, bitmask); sbi(reg, bitmask);
+
+#define cport(port, data) port &= data
+#define sport(port, data) port |= data
+
+#define swap(type, i, j) {type t = i; i = j; j = t;}
+
+#define fontbyte(x) pgm_read_byte(&cfont.font[x])  
+
+#define regtype volatile uint8_t
+#define regsize uint8_t
+#define bitmapdatatype unsigned int*