Define SHLIBDIR?= ${LIBDIR} and install shared libraries in
${DESTDIR}${SHLIBDIR} instead of in ${DESTDIR}${LIBDIR}.
SHLIBDIR may be defined in /etc/make.conf to override the
default of /usr/lib (I use /lib). Other changes are required
for non-default shared library directories to actually work
(ld* and crtso have too many hard-coded paths).
Bruce