This is a general tidyup to detach this fork better from Gordon, who was (and perhaps still is) completely inundated with WiringPi-related support questions.

This changeset includes a number of tweaks which should reduce support burden on Gordon. I believe they are essential if we plan to release a new debian package.

They should - hopefully - not reduce or make ambiguous the origins of this code while achieving the above.

* Remove Gordon's email address from all source files to avoid support queries finding their way to him
* Update wiringPi URLs to the GitHub repository to try and keep bugs/issues within the fork
* Bump version to 2.70 ready for a debian package release
* Update debian package maintainer info, add bugs & homepage URLs to this repository

* Changes to support the Zero 2 W (model type 18|0x12)

* Increment version in version.h

* Increment version in debian-template/wiringPi/DEBIAN/control

* Increment version in VERSION as well - I keep missing places where this number is defined

* Increment VERSION_MINOR, missed in previous commits; add missing Pi Z2W model name to piModelNames

Co-authored-by: schwartz <pi@schwartz>
Co-authored-by: PumpkinPi <jack@mirkwood.net>

Now that the upstream maintainer has abandoned this project without
establishing another maintainer, its difficult to choose an appropriate
version number. Going with 2.60 for now, as this only has incremental
changes to support 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.

Added fixed for a few minor things. pin driver for rht03/dht type
sensors. Network stuff is experimental - for now.

Fixed some compiler warnings.
New wiringPi version mechanism.
Put 4800 baud (back) into the system.
Re-added piBoardRev (really an alias of piGpioLayout())