Refactor do-package

[bapt]

Summary

Now each files generated are explicit targets

This would allow to simply loop over a list of packages for subpackages to
create them.

Remove the code for transition from pkg_install to pkg packages

The latest symlink is now a specific target only set when needed

[mat]

Mk/bsd.port.mk

3337

extra empty line

[swills]

Looks great, tested locally and it works fine. Fix the blank line. :)