Improve parsing of Java command lines
-Djdk.java.options= is now handled, making mvnd report as "Launcher".
Correct but not super helpful. An improvement on what was there before
though which was just wrong.
Also, improve parsing of `last` output to work on Raspbian.

Handle broken-pipe situations in px
This release comes with two changes:
- Handle broken-pipe situations in px
- Improve "node" command line parsing

Stop failing silently when `last` is missing

Fix a CI failure

Fix source wheel builds
In the previous release, building from source wheels got you the wrong
version number. That has now been fixed.

Fix build script
Building after cloning was sometimes failing in 3.6.6.

Parse Guile command lines
Cred to @daym in #131!

Make setup.py generate px/version.py
Back to how it used to be. This fixes a brew build failure.

Rethink handling of future processes
Before this change, during both testing and runtime we asserted on
processes created in the future.
Since this randomly failed in CI, and possibly for some users as well,
those checks have now been moved to local testing only. Note that I
have been thinking about this but never managed to figure it out, so
hiding it is my best bet for now...

Improve command line parsing
Specifically of zsh scripts and brew.sh invocations.