pgstatspack - pgstatspack: fix issue with uninstalled module

Log Message:
-----------
fix issue with uninstalled module pg_stat_statements on 8.4

Modified Files:
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pgstatspack:
pgstatspack_README.txt (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatspack/pgstatspack/pgstatspack_README.txt?r1=1.5&r2=1.6)
pgstatspack/bin:
pgstatspack_report.sh (r1.4 -> r1.5)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatspack/pgstatspack/bin/pgstatspack_report.sh?r1=1.4&r2=1.5)
pgstatspack/sql:
pgstatspack_create_snap.sql (r1.3 -> r1.4)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatspack/pgstatspack/sql/pgstatspack_create_snap.sql?r1=1.3&r2=1.4)