Fix rebinding to entities/policies living in OSGi bundles

When an entity/policy is created from a catalog item we make a note of its related catalog item id. On rebind we use that information to get the class loading context from the corresponding catalog item so that classes from OSGi bundles referenced in the item config are accessible.
Look in parent entities when looking for a context catalog id to load classes from.
Use explicit property for context catalog id bookkeeping

Move from using tags to set the context catalog id to explicit properties.
Make a note of the remaining steps needed for reliable rebind + OSGi bundles.
Set the catalog item id used when creating BOSpecs
Fix compile warnings
Initialize the context catalog item id when adding items to the BO hierarchy.
Initialize the context catalog item id from the current task's context entity.
Fix Cassandra v2

- roll back to 2.0.9
- let bin/cassandra write pid, rather than us writing pid
BrooklynNode cluster + upgrade effector

Also effectors to:
  * select master in the cluster
  * set HA priority
  * set HA state
add an upgrade effector for the BrooklynNode, and a sample yaml, and improve lifecycle so that stop_* methods destroy the VM and set a STOPPING state
clean up of anonymous internal classes, and some minor extensions to predicates available on Entity and String
minor cleanups to software, allowing start with no locations, and including stdin for driver.execute commands
main cleanup of brooklyn HA and upgrade
fix bug where tasks (eg pollers) are not stopped on unmanagement if the task which started the tasks is the same one which is unmanaging the entity
add support for extra CLI parameters to BrooklynNode, use those to run in persistence mode, and final fixes to the in-place upgrade effector
bunch of clean ups - mainly addressing @aledsage's comments on @neykov's cluster upgrade PR, plus misc things i've noticed.
needs further testing though.
fix swallowed error in dynamic cluster
clean up process of setting up the new-version cluster
more QuorumCheck to util package, using it for new CollectionFunctionals defining a predicate which applies a predicate to a collection