pgstatspack - pgstatspack: install update for 2.3.1

Log Message:
-----------
install update for 2.3.1

Modified Files:
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pgstatspack:
upgrade_pgstatspack.sh (r1.9 -> r1.10)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatspack/pgstatspack/upgrade_pgstatspack.sh?r1=1.9&r2=1.10)
pgstatspack/sql:
pgstatspack_create_tables.sql (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatspack/pgstatspack/sql/pgstatspack_create_tables.sql?r1=1.5&r2=1.6)