Petals Distribution

The runtime architecture of a bus in terms of container is described using a topology. Currently, a topology is made of a domain and subdomains: the idea being that one subdomain is attached to one registry (and thus one implementation of it) and can see each others. The domain was the complete bus The objective was to enable communication between subdomains at one point. In practice, this has never been implemented, and the concept of subdomain doesn't bring anything that the concept of domain already bring. Moreover, after some discussion, it seems that it is better to use the concept of domains combined with a BC for propagating services inbetween them as described in PETALSDISTRIB-175. Hence, we should remove the concept of subdomains (as it is now) and move its current functionalities (such as containing containers, having a registry, attaching container to a subdomain, detaching, querying, etc) to the concept of domain. This will have impacts mainly on the Container (including JMX administration, topology definition and WS API extension) (PETALSESBCONT-351) and the Petals CLI (PETALSESBCLI-125). We should also take the opportunity to make the registry more independent of the style of the topology (PETALSREGOVER-7 and PETALSREGCLI-5).