Update many of the example files

- Updated gettingStarted examples to demonstrate proper pipe/address
handling by assigning a unique id to each node
- Updated gettingstarted_call_response to demonstrate 'proper' use of
ack payloads
- Added gettingstarted_handling_data example
- Added pingpair_irq_simple to demonstrate bidirectional communication
via interrupts
- Updated standard pingpair_irq example
- Use Serial.println(F()); instead of printf