Dev cluster config

[approxit]

What I've done:

• Created golem-cluster-dev.yaml file, with disabled registry stats and enabled project files sync
• Cleaned up some fields in cluster yaml files
• Added support for disabling registry stats on image resolution
• Added default value for auth/ssh_user field
• Fixed problem with disable_existing_loggers settings in logging facility, that made bunch of premature exit problems invisible
• Fixed problem with premature exit of managed yagna process due to SIGINT forwarding from parent to child subprocess, that made problems with clean GolemNode shutdown
• Fixed problem with premature webserver exit on self-shutdown, that made final exit logs not reachable
• Added more verbose logs of service lifetime
• Reformatted code

Notable remarks:

• Forcibly exiting webserver can leave yagna process running in the background
• Terminating nodes with ray down can have race condition with autoscaler in the background, and webserver self-shutdown can be called multiple times, exiting too early in result, witch raises ugly exception on ray down