Now that we have a shiny new PyOxidizer-based hgcli project, let's
customize it for Mercurial!
This commit replaces the auto-generated pyoxidizer.bzl with one
that installs Mercurial from the local source repository.
A README.md with build instructions has been added.
The Cargo.toml file has been updated to reflect the proper license
and reference the added README.md.
In my Linux environment, running the test suite yields 27 failures.
It's worth noting the run time of the test harness on Linux on my
Ryzen 3950X:
before: 378s wall; 9982s user; 1195s sys
after: 353s wall; 8996s user; 958s sys
% orig: 93.4 wall; 90.1 user; 80.2 sys
While I haven't measured explicitly, I suspect the performance win is
due to in-memory resource loading (which is known to be faster than
Python's filesystem importer).
It would be nice to have a comment abotu why this is necesssary (as for the other entry in this call)