pgsql: Allow non-superuser database owners to create procedural

Log Message:
-----------
Allow non-superuser database owners to create procedural languages.
A DBA is allowed to create a language in his database if it's marked
"tmpldbacreate" in pg_pltemplate.  The factory default is that this is set
for all standard trusted languages, but of course a superuser may adjust
the settings.  In service of this, add the long-foreseen owner column to
pg_language; renaming, dropping, and altering owner of a PL now follow
normal ownership rules instead of being superuser-only.
Jeremy Drake, with some editorialization by Tom Lane.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        catalogs.sgml (r2.147 -> r2.148)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml.diff?r1=2.147&r2=2.148)
    pgsql/doc/src/sgml/ref:
        alter_language.sgml (r1.6 -> r1.7)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/alter_language.sgml.diff?r1=1.6&r2=1.7)
        create_language.sgml (r1.43 -> r1.44)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_language.sgml.diff?r1=1.43&r2=1.44)
        drop_language.sgml (r1.24 -> r1.25)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/drop_language.sgml.diff?r1=1.24&r2=1.25)
    pgsql/src/backend/catalog:
        aclchk.c (r1.137 -> r1.138)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/aclchk.c.diff?r1=1.137&r2=1.138)
    pgsql/src/backend/commands:
        alter.c (r1.22 -> r1.23)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/alter.c.diff?r1=1.22&r2=1.23)
        proclang.c (r1.71 -> r1.72)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/proclang.c.diff?r1=1.71&r2=1.72)
    pgsql/src/backend/parser:
        gram.y (r2.583 -> r2.584)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y.diff?r1=2.583&r2=2.584)
    pgsql/src/backend/tcop:
        utility.c (r1.274 -> r1.275)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/utility.c.diff?r1=1.274&r2=1.275)
    pgsql/src/bin/pg_dump:
        pg_backup_archiver.c (r1.143 -> r1.144)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup_archiver.c.diff?r1=1.143&r2=1.144)
        pg_dump.c (r1.464 -> r1.465)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c.diff?r1=1.464&r2=1.465)
    pgsql/src/bin/psql:
        tab-complete.c (r1.159 -> r1.160)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/tab-complete.c.diff?r1=1.159&r2=1.160)
    pgsql/src/include/catalog:
        catversion.h (r1.394 -> r1.395)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.394&r2=1.395)
        pg_language.h (r1.29 -> r1.30)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_language.h.diff?r1=1.29&r2=1.30)
        pg_pltemplate.h (r1.3 -> r1.4)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_pltemplate.h.diff?r1=1.3&r2=1.4)
    pgsql/src/include/commands:
        proclang.h (r1.11 -> r1.12)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/proclang.h.diff?r1=1.11&r2=1.12)
    pgsql/src/include/utils:
        acl.h (r1.100 -> r1.101)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/acl.h.diff?r1=1.100&r2=1.101)