Remove duplication from InternalEntityFactory etc
Deprecate EntitySpec.id and LocationSpec.id

- Just let the management context decide what the id should be.
- Rebind goes through a different path.
Internal*Factory: remove duplication

- Remove duplication across InternalEntityFactory, InternalPolicyFactory
  and InternalLocationFactory
- Remove duplication in callers of InternalEntityFactory.createEntity
Remove duplication in rebind code
Change EntityAdjunct.getName() to getDisplayName()
Creating BrooklynObject super-type

- a super type for Entity, Location, Policy and Enricher
This closes #69

Conflicts:
	core/src/main/java/brooklyn/entity/proxying/InternalEntityFactory.java - imports
rat should ignore .repository (which is used by jenkins-mvn for instance)