- platforms other than NetBSD (Linux, and FreeBSD)?

  PFKEYV2 and XFRM are pretty esoteric.

- /etc/ipsec*

  ipsec.conf, ipsec.secrets and ipsec.d/*

- logrotate https://github.com/libreswan/libreswan/issues/767

  It's a weak dependency / suggested package.  If libreswan is
  using syslog, say, it isn't needed.

  During install, libreswan creates logrotate.d and then installs
  a logrotate file.  It doesn't install the file in examples
  (which begs the question where).

- fix handling of config files - install into share/examples/libreswan
  and use CONF_FILES
