Microsoft-CISL/REEF — pull request #766 by markusweimer (2014-04-23 21:25:34+00:00)
Title: Exception handling improvements

**This closes #760:**
* Added an interface `ExceptionCodec` which shall be used to (de-)serialize Exceptions. This replaces the use of `ObjectSerializableCode`. The interface returns `Optional` upon deserialization, thereby geving a clean hint as to whether the Exception can be deserialized.
* Added a default implementation of `ExceptionCoded` called `DefaultExceptionCodec` which does use Java Serialization.
* Used an injected `ExceptionCodec` in all places where Exceptions were (de-)serialized using `ObjectSerializableCode`

**Refactorings:**
* Cleaned up the message passways in `EvaluatorManager` into more special cased methods like `.onEvaluatorFailed()`
* Improved failure logging in the `FailTaskTest` `Driver`.