pgevent fixes:

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