add CreateNamedPipe(), ConnectNamedPipe(), DisconnectNamedPipe()

[kjk]

Hi Rodrigo, great project.

I needed those functions so adding.

I made result of CreateNamedPipe an HFILE because I need to call ReadFile() on it.

It could also return HANDLE or a new type HPIPE but if it was HPIPE, would need to duplicate ReadFile, CloseHandle etc.

Not sure if ConnectNamedPipe() should be methods on HFILE, I made them straightforward args.

[kjk]

Thanks!