hgcli: customize for Mercurial 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). Differential Revision: https://phab.mercurial-scm.org/D8351