process http request for perf data logged from LoggingScope. Allow to access driver log files through http request.

This is to address issue REEF-29 https://issues.apache.org/jira/i#browse/REEF-29?filter=-1

Author: Julia Wang
email: jwang98052@yahoo.com

- changing jettyHandler in HttpServerImpl into non-static
- use REEFFileNames for log file names
- process http request for perf data
- address review comments for format issues

Closes #15
[REEF-3] Create basic Task scheduler as an example

  The current Task scheduler example only supports one evaluator
  at a time. This pull request addresses this issue to run multiple
  evaluators simultaneously and introduce a new REST interface to
  dynamically set the maximum number of evaluator.

  * The new API : `/reef-example-scheduler/v1/max-eval?num={num}`.
  * Quite a lot of code rearrange and refactoring are done.

JIRA:
  [REEF-3] https://issues.apache.org/jira/browse/REEF-3

Pull Request
  #23 https://github.com/apache/incubator-reef/pull/23

Closes #23
[REEF-33] Allow Tasks to initiate an Evaluator Heartbeat

  This adds the class HeartBeatTriggerManager which can be used by a Task to
  initiate an Evaluator Heartbeat. It is used by injecting it into the Task.

JIRA:
  [REEF-33] https://issues.apache.org/jira/browse/REEF-33

Pull Request:
  Closes #24
[REEF-52]: Remove default implementation annotation on HTTPServer
  There shouldn't be a default implementation on HttpServer to make sure we get
  an early error if it isn't configured. This removes that annotation.

JIRA:
  [REEF-52]: https://issues.apache.org/jira/browse/REEF-52

Pull Request:
  Closes #26
[REEF-53]: Currently there is no interface for NameServer. And all the parameters of
the NameServer have default values. This means as long as a client puts NameServer in the
Driver constructor, no matter it is binded or not, it will be started.

This introduces NameServer interface and renames original NameServer as NameServerImpl,
so that if NameServer is not in a Driver constructor and clients do not bind NameServerImpl
into Driver configuration, NameServer will be not started.

- Introduce NameServer interface and add default Name Server implementation
- remove DefaultNameServerImpl

Author: Julia Wang jwang98052@yahoo.com

JIRA:
  [REEF-53]: https://issues.apache.org/jira/browse/REEF-53

Pull Request:
  Closes #27
[REEF-56]: Removed the shaded and test jar creation in reef-tests The prior
  addition of the `-test-jar-with-dependencies` replaces both of them. Hence,
  their creation has become redundant

JIRA:
  [REEF-56]: https://issues.apache.org/jira/browse/REEF-56

Pull Request:
  Closes #29

Author:
  Markus Weimer weimer@apache.org
Passing HttpServer port number over the bridge. It contains the changes on ClrBridge, JobDriver and Driver.dll as ClrSystemHandlerWrapper is changed
Closes #30
This checkin resolves issue #REEF-51
Author:    Julia Wang <jwang98052@yahoo.com>
[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