rust-chg: spawn server process if not running...
rust-chg: spawn server process if not running
This is the minimal reimplementation of gethgcmd(), execcmdserver(),
retryconnectcmdserver(), and connectcmdserver() in chg.c.
No config validation is implemented yet. And some Py3 workarounds would
be missing as this is the code I wrote in 2018.
Differential Revision:
https://phab.mercurial-scm.org/D8360
