Disable JcloudsLocation opening iptables rules

- Allow it to be enabled via config OPEN_IPTABLES, but by default it's
  disabled.
- It was breaking things (due to `sudo -n` on centos, which needs fixed
  separately), when using jclouds to ssh to machine as part of creating
  the VM.
- It's needed for (some) RHEL VMs
TomcatServer live test: code tidy
fixed webapp integration tests, and refactored so easier to run just some, and to extend
fix integration tests which break because of locations needing to be managed
add support for jetty6 (quite old, but needed for acunu); also add an AddingEnricher which adds # of 400's with # of 500's to produce # of errors;
minor fixes to other webapp items
Merge pull request #819 from ahgittin/fix/integration-tests

fixes to webapp integration tests
code review comments for #819 and #820
Merge pull request #820 from ahgittin/feature/jetty

jetty appserver
minor tidies for cassandra
suppress membership-change notifications on unchanged service-up events (removes quite a bit of unnecessary processing and logging) and toString for better logging
tidies for api convenience around enrichers and sensor/feeds, and better logging (esp around location problems)
allow a grace period for sensors logging at WARN level if we haven't received any successful responses yet
Merge pull request #821 from ahgittin/fix/misc3

api conveniences, cassandra tidies, and logging fixes
use a concurrent map for membership-tracking service-up cache
JcloudsLocation: log assignable locations on exception
Convert groovy to java: OpenShift and Whirr
Fix sandbox/dropwizard (after /rest module changes)
Adds DynamicCluster.INITIAL_QUORUM_SIZE

- So that start() doesn't fail with exception if all nodes don't 
  startup. Instead can configure how many are required out of the
  desired initialSize.
Use Entities.destroyAll(app.getManagementContext())

- instead of Entities.destroyAll(app)
AbstractLocation: fix assertNotYetManaged

- was not correctly tracking when inConstruction