Prep for deb release as 2.70

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

wiringPi/wiringPi.c

@@ -9,7 +9,7 @@
  *	the clock section /grr/mutter/
  ***********************************************************************
  * This file is part of wiringPi:
- *	https://projects.drogon.net/raspberry-pi/wiringpi/
+ *    https://github.com/WiringPi/WiringPi
  *
  *    wiringPi is free software: you can redistribute it and/or modify
  *    it under the terms of the GNU Lesser General Public License as
@@ -785,7 +785,7 @@ int piGpioLayout (void)
     fprintf (stderr, "Unable to determine hardware version. I see: %s,\n", line) ;
     fprintf (stderr, " - expecting BCM2708, BCM2709 or BCM2835.\n") ;
     fprintf (stderr, "If this is a genuine Raspberry Pi then please report this\n") ;
-    fprintf (stderr, "to projects@drogon.net. If this is not a Raspberry Pi then you\n") ;
+    fprintf (stderr, "at GitHub.com/wiringPi/wiringPi. If this is not a Raspberry Pi then you\n") ;
     fprintf (stderr, "are on your own as wiringPi is designed to support the\n") ;
     fprintf (stderr, "Raspberry Pi ONLY.\n") ;
     exit (EXIT_FAILURE) ;