added UniqueEntityEventSession in DefaultBatchedEventProcessor to ensure
only one task per entity in one batch (index and deletes for the same
entity in one batch produced unwanted states), had to provide access to
entity in Esi4jEntityTask to do so.
Merge branch 'master' into unique-entity-in-batches
extract ObjectKey from Esi4JEntityResolver
Merge remote-tracking branch 'origin/master' into unique-entity-in-batches
fixed bug in HibernateEntityResolver
added license header
moved session handling to new interface Esi4JSessionEntityResolver
doc
improved duplicate resolution in QueuedTaskExecutor
Merge pull request #6 from molindo/unique-entity-in-batches

added UniqueEntityEventSession in DefaultBatchedEventProcessor to ensure