Fix build into jails with DTRACE enabled.

PR:		190662
Submitted by:	Martin Vahi <martin.vahi@softf1.com>
Fix build on >= 10.0 by including required headers
- Bring back the .packlist files, many people need them, they will
  automatically added to the plists.
- Add soname to libperl.so and rename it to libperl.so.PERL_VER, for instance
  libperl.so.5.18. To keep software linked with it working, provide a
  libperl.so symlink.
- Rollback Perl's man page location change, it creates conflicts for the few
  modules that ship with Perl and are in the ports tree.

Sponsored by:	Absolight
And point man to the new right place.

Sponsored by:	Absolight
No need to output what this does.

Pointy hat to:	myself
Sponsored by:	Absolight