The SQL script that installs the PL/pgSQL language has the location of the
postgres library directory hard coded. This patch corrects the problem by
having configure generate the SQL script.
Affected Files (relative to the PGSQL base directory):
src/configure, src/configure.in
Deleted Files (relative to the PGSQL base directory):
src/pl/plpgsql/src/mklang.sql
New Files (relative to the PGSQL base directory):
src/pl/plgsql/src/mklang.sql.in