Add a new USE_LIBTOOL definition that uses the libtool package instead of
pkglibtool which is now considered outdated.
USE_PKGLIBTOOL is available for backwards compatibility with old packages
but is deprecated for new packages.
- 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.