Start a configurable number of "main" Squid processes. Each process

Start a configurable number of "main" Squid processes. Each process
does what a regular Squid daemon does. Listening conflicts are resolved
using a temporary hack (incrementing the port number for each process).

Restart dying processes as needed, maintaining the old overall daemon
restart logic and quitting on frequent repeated failures or successful
daemon completion.

Needs more work to polish restarting code, to share common resources
such as listening ports, to unify reporting, including logging. CPU
core affinity and process specialization need to be configurable.