SERVER-14886 BSONElementIterator::next() set array offset correctly
Import wiredtiger-wiredtiger-2.4.0-399-g225aa81.tar.gz from wiredtiger branch mongodb-2.8
SERVER-15496 Get rid of replLocalAuth()
SERVER-15496 Update old unit tests to use new ReplicaSetConfig
SERVER-15496 Remove legacy replication code
SERVER-15946 Get rid of GlobalSharedLockAcquirer in favor of taking the global lock directly
SERVER-15946 Don't acquire MMAPV1Flush lock when locking global shared lock for stepdown.
SERVER-15675 Remove OperationContext from UpdateRequest/DeleteRequest

The write execution machinery should have a handle to the operation
context, not the write request structs.
SERVER-15675 PlanStage::invalidate() needs OperationContext

PlanStage::invalidate() is always called by a different thread than
the stage's owning thread.  The method should use the active
OperationContext (the caller's) rather than the stage's
OperationContext.
SERVER-15675 Stages should clear their OperationContext in saveState()

While state is saved, threads pass in their own OperationContext to
invalidate().  When state is restored, the stage will resume with the
OperationContext passed in to restoreState().
SERVER-15861 add secondaryCatchUpPeriodSecs argument to replSetStepDown
SERVER-15946 add repro test for replSetStepDown without force argument will fail if secondaries are behind and there is any write load