Discovery of already existing spaces and context [need to be finished]

Correction of the bug related to the discovery of already existing
spaces.
The same patch must be apply for the context but a bug in context
instanciation is blocking the process. Code currently in comment.

Numerous issues related to this big commit
sarl/sarl#63
Janus issue #13 (partial)
Hommogenization of inject engine reference, all to Guice and asserts addition
Merge branch 'master' of https://github.com/janus-project/janusproject

Transforming provider class into provdiers methods
And updating SpaceRepository for preventing useless space instanciations
Continuation of Janus issue #13 (partial)
Fixing the header of the ZeroMQ messages.
Fixing a synchronization problem on the SpaceRepository.
Synnchronizing the kernel features.
Redesign the service API of the kernel.
Merge branch 'master'.
Redesigning the code of the platform to have better event-support between the services.
CLeaning the code according to the redesign.
First version after the redesign that is working on localhost.
The redesign is based on:
1) Determination of the list of the platform's services
2) Introduce listening among the services in place of the hard-coded method calls.
3) Try to restrict injection to services, and their components (except the agents and the spaces).
Enforce the stopping of the kernel.
Make the EventDispatch more robust: the custom headers must be stored into a modifiable map.
Activate the ZeroMQ layer.
Add synchronized collections on specific mutex.
Clean context creation.
Update Context Creation
Validate the event dispatching in the kernel; and the kernel/context/space discovery.
Ensure that the services are started/stopped in the correct order.
Fixing the ZeroMQ module.