Bulk Operation

REEF-686 Remove Org.Apache.REEF.Common.IJobMessageObserver

REEF-686 Remove Org.Apache.REEF.Common.FailedRuntime

REEF-686 Remove Org.Apache.REEF.Driver.FailedJob

REEF-686 IContext should be immutable

REEF-686 IClosedContext should be immutable

REEF-686 ITaskMessage should be immutable

REEF-686 *Task.ActiveContext should be read only

REEF-686 IEvaluatorRequest should be immutable

REEF-686 IEvaluatorDescriptor should be immutable

REEF-686 All constructors of EvaluatorRequest should be internal

REEF-686 EvaluatorDescriptorImpl should be internal

REEF-686 IEvaluatorRequestor.ResourceCatalog should be immutable

REEF-686 ICompletedTask.ActiveContext should be immutable

REEF-686 IRunningTask.ActiveContext needs to be immutable

REEF-686 Rationalize the two IRunningTask types

REEF-686 IIdentifiable should be immutable

REEF-686 IFailedEvaluator should be immutable