Modify benchtool to support testing transactions

Added 4 additional options to allow for enabling and configuring the usage of transactions.
tx turns on transactions and determines the commit mode, ta determines the number of actions before committing,
tp controls the number of concurrent transactions and pt causes setup/teardown steps to be performed as transactions.
Results reporting includes stats about transaction activity and a summary line for comparison between runs.
Updated .gitignore to exclude eclipse files and logs.
Reusing a single FedoraRestClient between all actions being measured.  Clients are now assigned a txManager rather than a tx, and the tx for a given worker is passed into the client methods.
Renamed Transaction classes to TransactionState to prevent confusion.
Removed datastream cleanup step since this is implicit when purging objects
Merge pull request #10 from bbpennel/transactions

Modify benchtool to support testing transactions