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/UTouch/hardware/pic32/HW_PIC32_defines.h

@@ -0,0 +1,12 @@
+// *** Hardwarespecific defines ***
+#define cbi(reg, bitmask) (*(reg + 1)) = bitmask
+#define sbi(reg, bitmask) (*(reg + 2)) = bitmask
+#define rbi(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 swap(type, i, j) {type t = i; i = j; j = t;}
+
+#define regtype volatile uint32_t
+#define regsize uint16_t