Update the list of files installed by "scons install-pytools", dropping Python2
versions and adding their Python3 replacements. This doesn't update any
`import` statements, as the tools have already been ported to use the Python3
modules - the scons script was out of date and was still bundling the wrong
versions.
Note for anyone looking at the history - although most of the current
tools have a '3' in the name just to indicate that they're the Python 3 version,
there's a double-meaning to that number in wmlparser3.py's name. There was a
`wmlparser2.py`, where the `2` indicates a redesign of the original.
The data/tools/README.md file was renamed from plain README without being
converted to Markdown format. This commit touches about half of that file;
headings in that half are updated to be Markdown, but to reduce the diff the
other headings aren't updated.
It seems unused, as there's:
* Wiki: no mention of rmtrans
* main Git repo: only the brief paragraph in the tools readme
* resources repo: no mention of it
* forums: only as part of a general list of Python files
* Github issues and PRs: only as part of a general list of Python files
FWIW, I think it's already possible to do with Gimp's default tools ("Colors",
"Curves ...", select channel "Alpha", select curve type "Freehand", click in
the bottom-left of the box and sweep down, then to the left edge of the box,
then as far right as required).
