TODO: That's not clean, find another way to make this available for othercode.

NewProcess creates a new process from a command */.

NewPM creates a new PM.

RegisterCmd registers a new command (extension) so it can be executed via commands */.

UnregisterCmd removes an extension from the global registery */.

Global command ProcessConstructor registery */.

PM is the main process manager.

MeterHandler represents a callback type.

ResultHandler represents a callback type.

StatsFlushHandler represents a callback type.