introduce the monitoring business logic

Nuxeo monitoring is based onto JMX standard.
From now, we already introduced a runtime management service that mainly helps you publishing POJO beans in JMX (see NXP-2981).
So, we're now going to define our own business.

Here is the main features we want to cover

• inventory
• status
• accounting

The service inventory will be mainly based onto the runtime service that is the component registry.
It will mainly adapt the registration objects graph (components, extension points, contributions) as an mbean tree.

The service inventory will be completed with service status. The main sources of information for that will be
the runtime service and the audit service. The runtime service manage the service bootstrap and can report
information about. The other natural source of information will be the audit, that logs events issued by services.
We also want to be able to test the service quality by by running a basic test case onto the service. This will be
the quality states. There is no dedicated place for in the system from now.

The service inventory will be also completed by accounting informations. The first kind of accounting information will
be provided directly by services. It's the accounting information that they can easily provide to users with no costs overhead.
As example, directory manager provide already core sessions counters. The second kind of accounting information will be built
over audit service. As events are logged into, we can extract indicators from them by executing some kind of pro stock logic.