[new] net/fnc 0.4 - like tog/tig but for fossil

Hi,

This is a new port "net/fnc", which is the fossil equivalent to tog/tig.

cat DESCR:
A read-only ncurses browser for fossil repositories in the terminal.

Homepage: https://fnc.bsdbox.org (with screenshots)

The author "mark" is also OpenBSD user.

Port notes:
* Patched out -O2
* The configure system cannot be convinced to *not* install the manpage
to /share/man. I decided to install manually instead of patching the
configure script because it's only two files.
* The post-extract mv is there because the distfile extracts to something
like fnc_2021-10-31_122120_3cc00310ea, which will change on every update.
* gcc-archs: I disabled compile-commands, because the feature is only
available in clang (-MJ)
* gcc-archs: I patched out -Werror because libfossil won't compile warning
free.

portcheck: ok
lib-depends-check: ok
functional test: ok (amd64 and sparc64)

I'm using fossil myself and would take MAINTAINER.

OK?

Best regards,
Stefan