River 3.0 change to River 2.3.0

[Peter]

Since the River 3.0 change indicates a breaking change, and as of my 
recent commit, we no longer have any pubic api breaking changes, I 
propose that we change the release version to River 2.3.0-beta

Note the changes from com.sun.jini to org.apache.river are not 
considered public api by the community, as was also Sun's policy.

The Startable interface is also an implementation detail, that River's 
services use.

While I can't guarantee that recent reversions haven't reintroduced 
unsafe publication of remote events, I would hope that other changes 
made to the codebase since, would still ensure safe publication of 
remote events.

Regards,

Peter.