A lot of time went into this gem to find changes in a
vanilla FreeBSD tree and to pick them up via the config
files provided by OPNsense and its current ports tree.

A vanilla tree is expected under /usr/freebsd-ports as
well as the standard layout of OPNsense.  If not the case,
the config vars can be edited to adapt to your directory
structure.

A known weakness of this script is its thoughtlessness
in case a port does an include-some-other-Makefile trick,
e.g. vim-lite to vim or gettext-runtime to gettext.  The
issue has been amended by marking these ports `sync' in
our ports.conf in opnsense/tools.git.  A better fix would
require a substantial rework of the ports infrastructure,
something that I don't think will happen.

Ports that are marked `sync' will also never update their
dependencies, as this would e.g. in the case of vim pull
in a lot of Xorg glue.

In any case it works reliably now.  :)

It depends on OpenSSL, which should be removed from base, so as
a starting point remove OpenSSH.  Removing OpenSSL from base has
a WITHOUT_CRYPT switch, which--surprise, surprise--doesn't work.
More work here soon.

We need to keep track of new and old binaries and directories.
This script will show removed and added files, but really only
the removed files are interesting as they must be stripped from
the system to not cause any harm (think vulnerable libraries
like OpenSSL from base we want to get rid of soon).

Prominent change is that we individually disable certain options and
bring back PERL, since we build it anyway.  As long as it isn't installed
by default it's good.  git will then pull it in and gets more usable,
e.g. `git add -p'.

Always sync OpenSSL as well just to make sure...

it is already there.  Make sure it matches in the
future by raising version awareness.

Here we stuff a directory into the path.  This is especially useful
when we are going to cross-build.  mips and arm, anyone?  ;)

FreeBSD still has 9600 as the default but most BIOS implementations
use 115200 these days.  If you need something else feel free to tweak
it as needed.

'tis a bit hard to anticipate the exact cleaning needs so
fully modularise the options via command line arguments.
Naming should be pretty simple and self-explanatory though.

which is currently being used for extra strongswan configure foo.