SERVER-13641 Add warning to commit methods on Transaction
SERVER-13643 RIP BSONElementManipulator

If you really need to manipulate a BSONElement, do your own const_casting
SERVER-13643 Remove getDur() where we already have a TransactionExperiment
SERVER-13643 Use TransactionExperiment in dropDatabase()
SERVER-13643 Use TransactionExperiment in ExtentManager
SERVER-13643 Use TransactionExperiment in setHead()