fix saveIptablesRules
addressed comments for saveIpTablesRules
Show effector param scroll bars only when necessary.

Previously the scroll bars were always visible making the forms unusable. It's still the case when there is a lot of content in the field.
Fix ServiceFailureDetector

- restore logic to remember last published event, so can take that
  into account for stabilisation delays
- fix races/timing in tests
This closes #62
This closes #257
Add timeouts to Networking.isPortAvailable

- was taking 1min 15secs for isPortAvailable(null, 8081)
- now has 250ms timeout for each check
- does log.trace to indicate time taken for each InetAddress:port
This closes #259
This closes #256
add Dockerfile