USE_PKGINSTALL is "YES". bsd.pkg.install.mk will no longer automatically
pick up a INSTALL/DEINSTALL script in the package directory and assume that
you want it for the corresponding *_EXTRA_TMPL variable.
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>.
programmable, interactive system well-suited to the construction of
text-based adventure games, conferencing systems, and other collaborative
software. Provided by Ben Collver <collver@linuxfreemail.com>.
Together with the previous commits, this closes his PR pkg/13073.