Lib new features and improved test example

- New lib functionality’s
   . New: negate registers
   . New: shift all registers
   . New: auto update with delay
   . New: integrate test sequence

- Improved example:
   . Run a sequence of operations for circuit composed of 2 cascaded
registers for a total of 16 serialized LEDs
   . Various operations with / without auto update
   . Shows individual / per register / and global operations
   . Commented examples
   . Comes with photos and a video