Use a nicer pelita URL scheme for network bots

[Debilski]

Having to type remote:tcp://10.10.10.1:12345 is very unwieldy and arcane. Using pelita://10.10.10.1:12345 would be an improvement. (Or we get rid of the URL scheme altogether.)

Additionally, we should err with a better message in case the IP address is not valid (number missing, etc.).