pgsql: plpgsql does OUT parameters, as per my proposal a few weeks ago.

Log Message:
-----------
plpgsql does OUT parameters, as per my proposal a few weeks ago.

Modified Files:
--------------
pgsql/doc/src/sgml:
plpgsql.sgml (r1.62 -> r1.63)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/plpgsql.sgml.diff?r1=1.62&r2=1.63)
pgsql/src/backend/utils/fmgr:
funcapi.c (r1.19 -> r1.20)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/fmgr/funcapi.c.diff?r1=1.19&r2=1.20)
pgsql/src/include:
funcapi.h (r1.16 -> r1.17)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/funcapi.h.diff?r1=1.16&r2=1.17)
pgsql/src/pl/plpgsql/src:
gram.y (r1.66 -> r1.67)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/gram.y.diff?r1=1.66&r2=1.67)
pl_comp.c (r1.85 -> r1.86)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_comp.c.diff?r1=1.85&r2=1.86)
pl_exec.c (r1.133 -> r1.134)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_exec.c.diff?r1=1.133&r2=1.134)
pl_funcs.c (r1.39 -> r1.40)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_funcs.c.diff?r1=1.39&r2=1.40)
plpgsql.h (r1.57 -> r1.58)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/plpgsql.h.diff?r1=1.57&r2=1.58)
pgsql/src/test/regress/expected:
plpgsql.out (r1.26 -> r1.27)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/plpgsql.out.diff?r1=1.26&r2=1.27)
pgsql/src/test/regress/sql:
plpgsql.sql (r1.21 -> r1.22)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/plpgsql.sql.diff?r1=1.21&r2=1.22)