Makefile: Allow DESTDIR for distribution package creation Build infrastructures for distribution package management like Debian and Redhat use DESTDIR to designate a virtual root directory for the package contents, as per the GNU convention: http://www.gnu.org/prep/standards/html_node/DESTDIR.html To specify a simple installation directory target, use INSTALLDIR instead. Also use "install" to create the directory if needed. Signed-off-by: Tormod Volden <debian.tormod@gmail.com>