pgsql: Increase the default value of default_statistics_target from 10

Log Message:
-----------
Increase the default value of default_statistics_target from 10 to 100,
and its maximum value from 1000 to 10000.  ALTER TABLE SET STATISTICS
similarly now allows a value up to 10000.  Per discussion.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        config.sgml (r1.199 -> r1.200)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/config.sgml?r1=1.199&r2=1.200)
        perform.sgml (r1.68 -> r1.69)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/perform.sgml?r1=1.68&r2=1.69)
    pgsql/doc/src/sgml/ref:
        alter_table.sgml (r1.101 -> r1.102)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/alter_table.sgml?r1=1.101&r2=1.102)
        analyze.sgml (r1.24 -> r1.25)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/analyze.sgml?r1=1.24&r2=1.25)
    pgsql/src/backend/commands:
        analyze.c (r1.128 -> r1.129)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/analyze.c?r1=1.128&r2=1.129)
        tablecmds.c (r1.272 -> r1.273)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c?r1=1.272&r2=1.273)
    pgsql/src/backend/tsearch:
        ts_typanalyze.c (r1.3 -> r1.4)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/tsearch/ts_typanalyze.c?r1=1.3&r2=1.4)
    pgsql/src/backend/utils/misc:
        guc.c (r1.482 -> r1.483)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c?r1=1.482&r2=1.483)
        postgresql.conf.sample (r1.247 -> r1.248)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/postgresql.conf.sample?r1=1.247&r2=1.248)