HA policies: use ConfigKeys
Adds config for ServiceReplacer.SET_ON_FIRE_ON_FAILURE
Improve test coverage for ServiceReplacer/ServiceRestarter
JcloudsLocation: No NPE if setup.script is given but not setup.script.vars
Correct typo in Reference and remove duplicate pom dependency in test-support.
Adds MACHINE_CREATE_ATTEMPTS JcloudsLocation config

Use to retry VM creation when exceptions are thrown, e.g. when AWS VMs
are dead on arrival. (Has successfully kept at least one run of
brooklyn-marklogic demo on track.)
Cleanup AbstractGeoDnsService.addTargetHost

- avoid NPE when hostname==null and ip!=null, and !USE_HOSTNAMES
- improve logging, so if log about hostname missing and then subsequent
  can't infer geo, then still log about the latter.
- general code cleanup; but more could be done.
Support overriding SoftwareProcessImpl.stop

- With the new task refactoring, the start/stop/restart effector
  constant also supplied the implementation, so the SoftwareProcessImpl's
  method wasn't invoked!
  Therefore overriding the method had no effect.
- Changes that, so one can override `doStop()` etc
- Makes start/stop/restart methods final
Merge pull request #965 from ahgittin/fix/misc

fix/misc
Merge pull request #957 from aledsage/fix/ha-policy-cleanup

Fix: HA policy cleanup
Merge pull request #967 from aledsage/fix/Overriding-SoftwareProcess.stop

Support overriding SoftwareProcessImpl.stop
Retry VM creation: Addressed review comments, added unit test.
Merge pull request #964 from sjcorbett/retry-vm-create

Retry vm create
Merge pull request #966 from aledsage/fix/AbstractGeoDnsService-addTarget

Cleanup AbstractGeoDnsService.addTargetHost
Merge pull request #960 from ahgittin/feature/camp

Support for rolling out complex apps (including 3-tier) described in CAMP YAML
Add metrics to cassandra node/cluster
Merge pull request #971 from aledsage/feature/cassandra-aggregated-metrics

Adds more enrichers/attributes to cassandra node/cluster
Tidy impl of location.newSubLocation

- deprecate LocationCreationUtils
- use LocationSpec (e.g. in JcloudsLocation)
Add AvailabilityZoneExtension (including aws impl)
Add InterAvailabilityZoneDynamicCluster