Initial work on Riak entities
added customisations and added new live test
added private IP as an EC2 fix
added basic riak cluster control join/leave cluster
fixed debian path problem + added test for GCE
ControlledDynamicWebAppCluster: add SERVICE_STATE

- Was seeing cluster getting "on-fire" icon in web-console sometimes.
  Was probably caused by propagating SERVICE_STATE from cluster
  and SERVICE_UP from load balancer - if values didn't agree then 
  would fail.
- However, before realising that (!) I fixed it by adding SERVICE_STATE
  explicitly in start/stop, in much the same way as AbstractApplication
  does it.
DynamicCluster: fix serviceState order

- Change order of setting SERVICE_STATE and SERVICE_UP. If set 
  RUNNING before serviceUp=true, then web-console infers that as
  a failure and can mark entity as in flames.
removed no shutDown on exit for tests
added RiakClusterExample
removed tearDown override + added cluster checks
added check if Riak node is in cluster before joining
Merge branch 'zaid-riak' of github.com:ZaidM/brooklyn into zaid-riak
minor fixes
added check for node in cluster before leaving
fixed cluster control functionality + minor fixes
added sensors + fixed cluster control + added recovernode effector
set default riak member spec
Adds enricher config Propagator.PROPAGATING

- useful for yaml
Failing test demonstrating ResourceUtil not following 301s
Improve HttpLatencyDetectorTest