03.04.2013 awe
Bugzilla ticket: 405353
Problem:
When two Scout servers must communicate with each other, we'd like to use Scout services with the same proxying mechanism as a
Scout client (ClientProxyServiceFactory). A real-life example is when a local (or offline) server must call a service-method on
a remote scout server.

Solution:
Provide a ServerProxyServiceFactory, which works like the ClientProxyServiceFactory. To avoid code duplication we move common
classes to a new plugin 'org.eclipse.scout.rt.servicetunnel'. The existing plugin 'org.eclipse.scout.rt.client' has a dependency
to this plugin. The ClientProxyServiceFactory extends the new base class BaseProxyServiceFactory. A Scout server plugin may
have an optional dependecy to the new servicetunnel plugin when server-2-server communication is required.

Migration:
None