Add the first version of the service conversations.

...on/serviceconversation/BidirectinoalServiceMessenger.java

...emsx/cisd/common/serviceconversation/ClientMessenger.java

...msx/cisd/common/serviceconversation/IClientMessenger.java

...sx/cisd/common/serviceconversation/ISendingMessenger.java

...ch/systemsx/cisd/common/serviceconversation/IService.java

...emsx/cisd/common/serviceconversation/IServiceFactory.java

...sx/cisd/common/serviceconversation/IServiceMessenger.java

...on/serviceconversation/ServiceConversationCollection.java

...common/serviceconversation/ServiceConversationRecord.java

...common/serviceconversation/ServiceExecutionException.java

...temsx/cisd/common/serviceconversation/ServiceMessage.java

...erviceconversation/UnexpectedMessagePayloadException.java

...viceconversation/UnknownServiceConversationException.java

...mmon/serviceconversation/UnknownServiceTypeException.java

...rviceconversarions/ServiceConversationCollectionTest.java