[REEF-75] Removed double quotes from the constructed local runtime Java
  classpath.  The double quotes caused difficulty when parsing the classpath
  via LocalClasspathProvider.

JIRA:
  [REEF-75]: https://issues.apache.org/jira/browse/REEF-75

Pull Request:
  Closes #36

Author:
  Brian Cho chobrian@apache.org
[REEF-74] This adds a more descritive text to the Exception thrown in
  EvaluatorControlHandler.

JIRA:
  [REEF-74] https://issues.apache.org/jira/browse/REEF-74

Pull Request:
  Closes #35

Author
  Markus Weimer weimer@apache.org
[REEF-72]: Make DriverIdentifier optional

This makes the DriverIdentifier optional. If it isn't set, we generate a unique one in JobSubmissionHelper.

JIRA:
  [REEF-72] https://issues.apache.org/jira/browse/REEF-72

Pull Request:
  Closes #34

Author:
  Markus Weimer weimer@apache.org