support IPCPrefixes rather than legacy IPCPort, IPCHost

[Luckz]

These need to get parsed somehow, and one has to be chosen. Just the first one? Assumes intelligent users.

Oh and why the fuck was it checking IPCHostname when the pref is called IPCHost? Did that get renamed or ..?

[Luckz]

Kestrel configuration nowadays lives in IPC.config.

[Luckz]

Oh and why the fuck was it checking IPCHostname when the pref is called IPCHost? Did that get renamed or ..?

Minor improvement in 38ed4e7