* Move all scripts and documentation to Python3
Python 2 EOL is Jan 1, 2020. Migrate scripts to run under Python 3.
Under Windows, we're already running Python 3.7, by dumb luck. The
oddness is that the Windows standalone executable for Python 3 is called
"python" whereas under UNIX-like OSes it's called "python3" with
"python" always referring to the Python 2 executable. The ZIP needs to
be updated to include a Python3.exe (copy of Python.exe) so that we can
use the same command lines under Linux and Windows, and to preserve my
sanity.
Fixes#6376
* Add new Windows ZIP with python3.exe file
* Sort options in boards.txt generation for repeatability
The order of the board opts dict changes depending on the Python version
and machine, so sort the options before printing them to get a stable
ordering.
* Re-add Python2 compatibility tweaks
Most scripts can run as Python 2 or Python 3 with minimal changes, so
re-add (and fix, as necessary) compatibility tweaks to the scripts.
* Upgrade to https: serving for JSON, links in docs
Fixes#5480
* Update boards.rst documentation
* Update more documentation http: refs to https:
* Remove obsolete staging info
* Drop obsolete versions from JSON programatically
After the final merge is done on the JSON, strip out any named versions
from the final product.
Removing 1.6.5-* and 2.5.0-beta(1,2,3) for now.
* Remove 2.4.0-rc(0/1) from JSON, too
* Add fix for SoftwareSerial submodule errors to documentation
* Update installing.rst
Replaces and based on #5602Fixes#5583
* Update installing.rst
Remove forgotten section
Add update section for Other OS
