logger subprocess including win32

Attached the patch, an orgy in #ifdefs, decorated with various indents
and crlf line ends (glad we have pgindent).

Remarks:
Log_destination for win32 is set to file, because stderr is equivalent
to /dev/null for services. This doesn't reflect correctly in
postgresql.conf.sample.

Log_destination=eventlog is like logging to /var/log/messages, you'd
make the sysadmin your enemy if he finds his app log flooded with
"NOTICE: created implicit index for pk". FYI: The size of the event log
is limited (default: 512k), cyclic overwriting can be selected, but *no*
rotation. Only really important messages should go there, not standard
logging. OTOH, really important messages *must* go there, so I changed
FATAL and PANIC messages to eventlog unconditionally.

Regards,
Andreas