Log Message:
Remove pkgsrc's attempt to force using libtool.

Postgresql upstream does not use libtool.  pkgsrc used to change
postgresql to use libtool, and this package was written to use the
pkgsrc-added libtool support.  pkgsrc no longer modifies postgresql to
use libtool, so postgis did not build.

In addition to backing out all the make-postgis-use-libtool packages,
this commit adds a patch to add rpath to the PGSQL_FE_LDFLAGS, which
upstream hand constructs from pg_config output.

PKGREVISION++, but no change in version or functionality (from the
previous state, which also didn't build) intended.