This change make the following commands correctly detect the 4B
however there may be an issue with reading GPIO inputs on the 4B
as they are always returning zero.

The aim of this change is to be the source-equivalent of the binary
package release 2.52[1] which was the last release before upstream
development ceased.

[1] http://wiringpi.com/wiringpi-updated-to-2-52-for-the-raspberry-pi-4b/

Sourced from http://archive.ubuntu.com/ubuntu/pool/universe/w/wiringpi/wiringpi_2.50.orig.tar.gz

Added gpio readall support for the Pi 0W.

for kernels 4.8 onwards.

Some very old stuff might break.

Additional fixes for the ISR code and some tweaks here and
there. I've removed the checks for some operations that might
fail when using the gpiomem interface - which is now the default
way of doing things - if your program segfaults, then you
may need to use sudo on it.

Updating the GPIO command - new command - allreadall
ScrollPhat code
max31855 code (tested with adafruit breakout board)
more tests
updated rht03 code

Raspberry Pi v3 support.

Added support for the ADS1115 16-bit ADC
Updated the gpio readall command to correctly with with the Compute Module
and fixed a resulting bug in wiringPi...

Moved the extensions into wiringPi from gpio and made it more general purpose
more so that RTB and anything else can dymanically add devices
into wiringPi.
Changes to GPIO to updates for the SPI and I2C module loads
Added gpio unload for SPI and I2C.

Added a new way to setup SPI - by passing the mode in.

Support for the new Pi2 thing too

round at last..

Updated for the 0x0012 board revision on the new A+

of changing it for the B+)

Aded a gpio command: usbp hi/low - to change the usb power

to produce a nicer 'readall' output too.

It also understands new pins 53,54,55 and 56 in wiringPiSetupPhys()
mode to represent the pins on the P5 connector on the Rev 2 Pi's

Changes to pinMode() to allow new modes SOFT_PWM and SOFT_TONE.

fixed the max5322 code.