have it be automatically included by bsd.pkg.mk if USE_PKGINSTALL is set
to "YES". This enforces the requirement that bsd.pkg.install.mk be
included at the end of a package Makefile. Idea suggested by Julio M.
Merino Vidal <jmmv at menta.net>.
- New, optional Makefile variable HOMEPAGE, specifies a URL for
the home page of the software if it has one.
- The value of HOMEPAGE is used to add a link from the
README.html files.
- pkglint updated to know about it. The "correct" location for
HOMEPAGE in the Makefile is after MAINTAINER, in that same
section.