Consul v1.6.1 and more

• Consul v1.6.1
• Add run_once to delegated tasks (thanks @liuxu623)
• Fix service restart on upgrades (thanks @jpiron)
• Fix log directory ownership (@thanks liuxu623)
• Handle missing unzip on control host (thanks @bbaassssiiee)
• Add Added version check for log_rotate_max_files (thanks @jasonneurohr)
  -Update documentation