rust: configure MSRV in Clippy
This setting makes Clippy never apply lints that are meant for
later versions. In case the target precise toolchain is the one
running, it does not make a difference, but this gives us a
machine-parseable specification that is pretty standard.
The README and `hg help rust` are updated to state that `clippy.toml`
is the single source of truth about that, also lifting a minor ambiguity:
it is fine if the MSRV is lagging behind the version in Debian testing.
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.
Notes for packagers
===================
Mercurial ships a copy of the python-zstandard sources. This is used to
provide support for zstd compression and decompression functionality. The
module is not intended to be replaced by the plain python-zstandard nor
is it intended to use a system zstd library. Patches can result in hard
to diagnose errors and are explicitly discouraged as unsupported
configuration.