chg: ignore HG_* in confighash
The environment variables `HG_*` are usually used by hooks. Unlike `HGPLAIN`
etc, they do not actually affect hg's behavior. So do not include them in
confighash.
This would avoid spawning an unbound number of chg server processes if
commit hook calls hg frequently.
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.