Objects counter

Added support for counting running objects on a machine by using the Job Manager.
This release break compatibility with POP-C++ Job Manager until the same feature is implemented there too.

Support for Resource Allocators

Now a Java JM need a ResourceAllocator to be passed when creating the centralized JM.

A Resource Allocator should implement the interface that come with the same name and be a POPClass.

@POPClass
public class RoundRobinAllocator implements ResourceAllocator {

The interface define two method, a registration one which is called when someone register on the JM and a next host use, used by the JM to know which host it should connect to in order to create a remote object.
See RoundRobinAllocator.java for an example.

Since popjava will not know the RA implementation at compile time it should be passed at runtime by creating the JM with the class name (string) and the POPAccessPoint of the allocator.

public POPJavaJobManager(String clazzString, POPAccessPoint pap)

Support for dynamic version of YARN

First release which support the dynamic allocation of containers.
Che communication between JM and AM is still a draft and currently work via a stdout catch on the AM part.

Make the YARN version work

Minor modification to the base code to make YARN work.
It's not yet tested in a standalone - w/o YARN - environment.