Win32 port

[Havoc Pennington]

Thiago Macieira wrote:
> 
> One thing, though, is that I've just realised the function is called 
> GetConnectionUnixUser, so it is only meaningful in Unix context. So we 
> can leave it, but I'd recommend adding a generic function too.
> 

I think just adding GetConnectionWindowsUser() might be fine ... there's 
nothing the caller can do without knowing whether it's getting unix or 
windows, since we aren't exporting any kind of uid abstraction outside 
of dbus internals.

One thing to check if doing this is the encoding of windows usernames... 
are they UTF-8 or UTF-16, or can they be in some other encoding...

Havoc