pgsql: First phase of OUT-parameters project.

Log Message:
-----------
First phase of OUT-parameters project.  We can now define and use SQL
functions with OUT parameters.  The various PLs still need work, as does
pg_dump.  Rudimentary docs and regression tests included.

Modified Files:
--------------
    pgsql/doc/src/sgml/ref:
        create_function.sgml (r1.64 -> r1.65)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_function.sgml.diff?r1=1.64&r2=1.65)
    pgsql/doc/src/sgml:
        xfunc.sgml (r1.101 -> r1.102)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/xfunc.sgml.diff?r1=1.101&r2=1.102)
    pgsql/src/backend/access/common:
        tupdesc.c (r1.109 -> r1.110)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/common/tupdesc.c.diff?r1=1.109&r2=1.110)
    pgsql/src/backend/catalog:
        pg_aggregate.c (r1.71 -> r1.72)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/pg_aggregate.c.diff?r1=1.71&r2=1.72)
        pg_proc.c (r1.125 -> r1.126)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/pg_proc.c.diff?r1=1.125&r2=1.126)
    pgsql/src/backend/commands:
        functioncmds.c (r1.58 -> r1.59)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/functioncmds.c.diff?r1=1.58&r2=1.59)
    pgsql/src/backend/executor:
        functions.c (r1.94 -> r1.95)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/functions.c.diff?r1=1.94&r2=1.95)
        nodeFunctionscan.c (r1.31 -> r1.32)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeFunctionscan.c.diff?r1=1.31&r2=1.32)
    pgsql/src/backend/optimizer/util:
        clauses.c (r1.191 -> r1.192)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/util/clauses.c.diff?r1=1.191&r2=1.192)
    pgsql/src/backend/parser:
        gram.y (r2.485 -> r2.486)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y.diff?r1=2.485&r2=2.486)
        parse_func.c (r1.176 -> r1.177)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/parse_func.c.diff?r1=1.176&r2=1.177)
        parse_relation.c (r1.102 -> r1.103)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/parse_relation.c.diff?r1=1.102&r2=1.103)
    pgsql/src/backend/utils/cache:
        lsyscache.c (r1.121 -> r1.122)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/lsyscache.c.diff?r1=1.121&r2=1.122)
    pgsql/src/backend/utils/fmgr:
        fmgr.c (r1.92 -> r1.93)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/fmgr/fmgr.c.diff?r1=1.92&r2=1.93)
        funcapi.c (r1.18 -> r1.19)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/fmgr/funcapi.c.diff?r1=1.18&r2=1.19)
    pgsql/src/include/catalog:
        pg_proc.h (r1.356 -> r1.357)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h.diff?r1=1.356&r2=1.357)
    pgsql/src/include/executor:
        functions.h (r1.24 -> r1.25)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/executor/functions.h.diff?r1=1.24&r2=1.25)
    pgsql/src/include:
        fmgr.h (r1.37 -> r1.38)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/fmgr.h.diff?r1=1.37&r2=1.38)
        funcapi.h (r1.15 -> r1.16)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/funcapi.h.diff?r1=1.15&r2=1.16)
    pgsql/src/include/utils:
        lsyscache.h (r1.95 -> r1.96)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/lsyscache.h.diff?r1=1.95&r2=1.96)
    pgsql/src/test/regress/expected:
        rangefuncs.out (r1.9 -> r1.10)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/rangefuncs.out.diff?r1=1.9&r2=1.10)
    pgsql/src/test/regress/output:
        create_function_2.source (r1.19 -> r1.20)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/output/create_function_2.source.diff?r1=1.19&r2=1.20)
    pgsql/src/test/regress/sql:
        rangefuncs.sql (r1.5 -> r1.6)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/rangefuncs.sql.diff?r1=1.5&r2=1.6)