plpsm - plpgpsm: merging Tom's patch

Log Message:
-----------
merging Tom's patch http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_exec.c.diff?r1=1.180.2.4&r2=1.180.2.5

Modified Files:
--------------
plpgpsm/src:
README.plpgpsm (r1.4 -> r1.5)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plpsm/plpgpsm/src/README.plpgpsm.diff?r1=1.4&r2=1.5)
pl_exec.c (r1.52 -> r1.53)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plpsm/plpgpsm/src/pl_exec.c.diff?r1=1.52&r2=1.53)