pgsql: Add per-user and per-database connection limit options.

Log Message:
-----------
Add per-user and per-database connection limit options.
This patch also includes preliminary update of pg_dumpall for roles.
Petr Jelinek, with review by Bruce Momjian and Tom Lane.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        catalogs.sgml (r2.109 -> r2.110)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml.diff?r1=2.109&r2=2.110)
    pgsql/doc/src/sgml/ref:
        alter_database.sgml (r1.15 -> r1.16)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/alter_database.sgml.diff?r1=1.15&r2=1.16)
        alter_role.sgml (r1.1 -> r1.2)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/alter_role.sgml.diff?r1=1.1&r2=1.2)
        alter_user.sgml (r1.38 -> r1.39)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/alter_user.sgml.diff?r1=1.38&r2=1.39)
        create_database.sgml (r1.43 -> r1.44)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_database.sgml.diff?r1=1.43&r2=1.44)
        create_role.sgml (r1.1 -> r1.2)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_role.sgml.diff?r1=1.1&r2=1.2)
        create_user.sgml (r1.37 -> r1.38)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_user.sgml.diff?r1=1.37&r2=1.38)
    pgsql/src/backend/access/transam:
        twophase.c (r1.8 -> r1.9)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/twophase.c.diff?r1=1.8&r2=1.9)
    pgsql/src/backend/catalog:
        system_views.sql (r1.17 -> r1.18)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/system_views.sql.diff?r1=1.17&r2=1.18)
    pgsql/src/backend/commands:
        dbcommands.c (r1.167 -> r1.168)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/dbcommands.c.diff?r1=1.167&r2=1.168)
        user.c (r1.159 -> r1.160)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/user.c.diff?r1=1.159&r2=1.160)
    pgsql/src/backend/nodes:
        copyfuncs.c (r1.312 -> r1.313)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/copyfuncs.c.diff?r1=1.312&r2=1.313)
        equalfuncs.c (r1.249 -> r1.250)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/equalfuncs.c.diff?r1=1.249&r2=1.250)
    pgsql/src/backend/parser:
        gram.y (r2.504 -> r2.505)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y.diff?r1=2.504&r2=2.505)
        keywords.c (r1.163 -> r1.164)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/keywords.c.diff?r1=1.163&r2=1.164)
    pgsql/src/backend/storage/ipc:
        procarray.c (r1.3 -> r1.4)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/procarray.c.diff?r1=1.3&r2=1.4)
    pgsql/src/backend/storage/lmgr:
        proc.c (r1.160 -> r1.161)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/lmgr/proc.c.diff?r1=1.160&r2=1.161)
    pgsql/src/backend/tcop:
        utility.c (r1.241 -> r1.242)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/utility.c.diff?r1=1.241&r2=1.242)
    pgsql/src/backend/utils/init:
        miscinit.c (r1.147 -> r1.148)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/miscinit.c.diff?r1=1.147&r2=1.148)
        postinit.c (r1.154 -> r1.155)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/postinit.c.diff?r1=1.154&r2=1.155)
    pgsql/src/bin/pg_dump:
        pg_dumpall.c (r1.65 -> r1.66)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dumpall.c.diff?r1=1.65&r2=1.66)
    pgsql/src/include/catalog:
        catversion.h (r1.293 -> r1.294)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.293&r2=1.294)
        pg_authid.h (r1.2 -> r1.3)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_authid.h.diff?r1=1.2&r2=1.3)
        pg_database.h (r1.36 -> r1.37)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_database.h.diff?r1=1.36&r2=1.37)
    pgsql/src/include/commands:
        dbcommands.h (r1.40 -> r1.41)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/dbcommands.h.diff?r1=1.40&r2=1.41)
    pgsql/src/include/nodes:
        nodes.h (r1.172 -> r1.173)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/nodes.h.diff?r1=1.172&r2=1.173)
        parsenodes.h (r1.286 -> r1.287)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/parsenodes.h.diff?r1=1.286&r2=1.287)
    pgsql/src/include/storage:
        proc.h (r1.79 -> r1.80)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/proc.h.diff?r1=1.79&r2=1.80)
        procarray.h (r1.2 -> r1.3)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/procarray.h.diff?r1=1.2&r2=1.3)
    pgsql/src/test/regress/expected:
        rules.out (r1.105 -> r1.106)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/rules.out.diff?r1=1.105&r2=1.106)