From: Tom Lane <tgl@sss.pgh.pa.us>

We're carrying around a copy of install-sh in case the local system
has no install script.  It's wasted baggage, because configure doesn't
know it's there :-(.  (Apparently everyone who's used postgres lately
already had an install script somewhere in their path.  I happened to
try to run configure with a minimal PATH tonight, and it promptly
gave up for lack of an install program.)  Here's the patch.