This allows different instances to use the eventlog with different
identifiers, by setting the event_source GUC, similar to how
syslog_ident works.
Original patch by MauMau, heavily modified by Magnus Hagander
1) Make vcbuild actually build the pgevent dll.
2) Change the pgevent DLL file so it doens't specify ordinal for the
functions. You're not supposed to do that. You're actually supposed to
declare them as PRIVATE as well, but mingw doesn't support that. VC++
will throw a warning and not an error though, so we can live with it.
Magnus Hagander
