Support for Client-Less Drivers

**API-Support for Client-less Drivers**
 * Deprecated REEF.close(), as this won't be supportable without a client
 * Renamed ClientManager to REEFImplementation
 * Added a JobSubmissionHelper to hold Protobuf code of REEFImplementation
 * Moved the launcher parameters into the 1st class space and added a default value to ErrorHandlerRID and ClientRemoteID
 * Added checks for NONE wherever the ClientRemoteID is used.

**Updated the Local Runtime to support Client-less Drivers**
 * Moved ExecutorServiceConstructor to no longer be an inner class.
 * Shutting down the executor in the LocalJobSubmissionHandler.

**Added a demo of how to use the new API**
 * Added a HelloREEFNoClient that contains the version without a client.
Merge branch 'master' of github.com:Microsoft-CISL/REEF into weimer_749

Conflicts:
	reef-common/src/main/java/com/microsoft/reef/runtime/common/driver/client/ClientConnection.java
 * Un-deprecated `REEF.close()`
 * Made sure that `RemoteManager.close()` is called as part of `REEF.close()` if one was created.
 * Added some more logging
Merge pull request #755 from Microsoft-CISL/weimer_749

Support for Client-Less Drivers