pgstatsinfo - pg_statsinfo: Fix a crash when the writer queue has two or

Log Message:
-----------
Fix a crash when the writer queue has two or more items.
Support additional fields in pg_stat_statement 9.0.
Move the call of fork() in port.c for platform portability.
Remark some TODO items are for the next release.

Modified Files:
--------------
pg_statsinfo/bin:
collector.c (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/bin/collector.c?r1=1.5&r2=1.6)
collector_sql.h (r1.2 -> r1.3)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/bin/collector_sql.h?r1=1.2&r2=1.3)
logger.c (r1.7 -> r1.8)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/bin/logger.c?r1=1.7&r2=1.8)
pg_statsrepo.sql (r1.3 -> r1.4)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/bin/pg_statsrepo.sql?r1=1.3&r2=1.4)
snapshot.c (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/bin/snapshot.c?r1=1.5&r2=1.6)
writer.c (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/bin/writer.c?r1=1.5&r2=1.6)
writer_sql.h (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/bin/writer_sql.h?r1=1.1&r2=1.2)
pg_statsinfo/lib:
libstatsinfo.c (r1.4 -> r1.5)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/lib/libstatsinfo.c?r1=1.4&r2=1.5)
libstatsinfo.h (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/lib/libstatsinfo.h?r1=1.1&r2=1.2)
port.c (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgstatsinfo/pg_statsinfo/lib/port.c?r1=1.1&r2=1.2)