Purpose:
Program to test GPIO modules on the LPC11xxLV
Tested on the LPC1101LV Development Board

Running mode:
* Compile, Flash the program and reset.
* Provide a single edge active low on GPIO ports (PIO1_4) to trigger a GPIO interrupt
* Push button (PIO1_4)available on the LPC1101LV Development Board

Output:
When an interrupt edge(single edge trigger, active low)occurs on the GPIO ports (PIO1_4), 
GPIO interrupt occurs.
