eventlog fix

Hello,

The purpose of this patch is to fix an error when log_destination is set to
'eventlog' value in postgresql.conf files.

If you launch postmaster and see after fir log in windows event report
tools, you will see an error message with postgresql message like that :

Sorry for this French copy screen, the error message is: description for id
event #0 is missing for PostgreSQL source.

To fix the error it is mandatory to describe and register a message with an
ID set to 0. The message is declared in a MC file whish need to be compiled
by MC compiler. The MC compiler is part of core SDK and is not available
with Msys tools but can be freely downloaded from Microsoft web site, so I
suggest storing in CVS msg00001.bin a bin file result of MC compiler.

The rest of DLL is functions to allow setup program to register/unregister
DLL to windows registry database after copy it in it's target directory.
(regsvr32 pgevent.dll to register, regsvr32 /u pgevent.dll to unregister
it).

After discussion on win32 mailing list, I suggest to store source under
src/bin/pg_event

regards,

Laurent Ballester