Various fixes for syslogger

Here are various fixes for syslogger.

- syslogger_parseArgs_assert.patch (bug #3621)
The assertion in syslogger_parseArgs() was wrong. The number of
arguments passed to syslogger is changed to 4 in 8.1 or later.
This patch should be appled to 8.1, 8.2 and 8.3dev.

- logfile_rotate.patch (bug #3622)
This patch fixes two bugs in the log file rotation.
This is only for 8.3dev.
1. pg_rotate_logfile() force log files to rotate. Both .log and .csv
files are treated the same way as size-limited rotation.
2. Fix a copy-and-paste bug in updating csvlogFile. CSV log was lost
after swiching files in all case of the rotations.

- remove_redirect_stderr.patch
redirect_stderr is renamed to logging_collector, but the old name
is left in postgresql.conf. This is only for 8.3dev.

BTW, I found empty .log files are created under $PGDATA/pg_log/ even if
log_destination does not contain 'stderr' (i.e, only csvlog or syslog).
Is this an intentional behavior?

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center