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

hgcli: add stub PyOxidizer project Using commit c772a1379c3026314eda1c8ea244b86c0658951d of PyOxidizer, I ran `pyoxidizer init-rust-project hgcli` to create a stub Rust project. The only modifications I made from what that command produced are: * Update location of pyembed crate to PyOxidizer's Git repository. * Removed some trailing whitespace from pyoxidizer.bzl * Added auto-generated Cargo.lock file Subsequent commits will modify the stub project to Mercurial's needs. Differential Revision: https://phab.mercurial-scm.org/D8350

hgcli: remove legacy project This code is a logical precursor to PyOxidizer. It is now defunct. Differential Revision: https://phab.mercurial-scm.org/D8349