bug 866459: Tweak retries and max jobs per process

This is a band-aid fix. It makes the service retry a failed macro 10 times instead of 3, and it allows workers to process 8 jobs instead of 64 before exiting. It also gives me a handle on the server instance from the telnet REPL, so I maybe can do some live debugging.

My working theory is that we're running into some resource limits from cumulative runs. Lowering max jobs should help avoid that, and raising the retries should make failure less likely since the issue seems to be transient.