Slony-win32 service

I have submitted a patch that runs Slony as a service on Win32. It supports multiple parallell engines (if you need to replicate more than one database) if needed.

Still needs a few things polished up (installation/uninstallation, registration of multiple engines etc) but I'd say win32 Slony is progressing very nicely. (Much of these things will probably be available in the installer and pgAdmin as well, but we'll need commandline interfaces as well)