Initial version of buttons and lights program.

When the buttons on D5,D6,D7 are pressed the leds on D2,D3,D4 are
illuminated.

The buttons are tied to ground and the leds are common cathode.

This program demonstrates the use of interrupts and the digital filter
to remove key bounce.
Split out pin_cb
Use pin_cb.
Ignore Eclipse files.
Added examples and extras.
Initialized pin in lights_cb.
Split into interrupt drive segments.
Formatting and comments.
Copied eclipse setup to winbond.
Tidied up.
Messed with eclipse to get access to GPIOB.ptor.