* Improve tests/pr test
* Add new function pr_open2 with argument "callback" ran from
child process immediately after fork(2) and before execvp(3).
* COPTS defaults to -O2 -g
* Add support for target "help", bump MKC_REQD to 0.34.0
* maa/log.c: fix compilation failure due to -Werror on
NetBSD-10.99.10 with gcc-10.5.0
* Move WARNS=4 to Makefile.common
* SUBPRJ_DFLT = maa test
* MAXHOSTNAMELEN can be already defined, limit to 64 characters
to avoid possible truncation.
