Revision history for Perl extension RPi::WiringPi.

0.05    2016-08-13
        - renamed WiringPi::pin_map() to gpio_scheme()
        - added WiringPi::gpio_map()
        - new()'s setup param now accepts 'none', allowing us to pypass the
          wiringPi's initialization
        - new Util.pm, moved all utility methods from WiringPi to Util.
          WiringPi now only handles SIGs and component objects
        - moved all param checking from Core into the respective modules here
          to keep Core as close to the C code as possible

0.04    2016-08-11
        - added LCD.pm module, for interfacing with LCD displays, along with
          a massive update to Core
        - changed LED::init() to just pass along the args hash, and let Core
          deal with any issues

0.03    2016-08-11
        - wrote RPi::WiringPi::Constant as a standalone module
        - added $SIG{__DIE__} handler so we can clean up properly on die()
        - added 'fatal_exit' new() param for testing
        - we now catch $SIG{INT} as well, with a test
        - new method pin_map(), returns the current pin mapping
        - tests now work on non-Pi boards (if wiringPi lib is installed)
        - implemented 
        - added Board.pm with methods rev(), wpi_to_gpio(), phys_to_gpio() and
          pwm_range()

0.02    2016-08-10
        - implemented getAlt() in Core, and in Pin, mode() with no params
          now returns the current mode of the pin
        - added cleanup()

0.01    2016-08-10
        - initial prototype release
        - added Pin.pm
        - added error checking
        - first round of tests
        - NO_BOARD env var
