Reimplement the Linux FIFO file server and client controls on Windows by using Named Pipes.
The DDNet server/client acts as a named pipe server and receives messages.
Messages can be posted to the named pipe server by connecting to it as a client.
The named pipe client can for instance be controlled from the command line with PowerShell.
The PowerShell script `scripts/send_named_pipe.ps1` is added for this purpose.
For example the PowerShell command `./send_named_pipe.ps1 "testpipe" "echo a"` sends the command `echo a` to the pipe named `testpipe`.
Multiple commands can be sent at the same time by separating them with semicolons or newlines.
