Modify UIMA-AS proxy code to make the collectionProcessingComplete a synchronous call

Current uima-as proxy code for CPC is asynchronous. The client using the proxy calls CPC and does not wait for reply from the service. The proxy must implement UimaASStatusCallbackListener interface and register self with the UIMA-AS client. The client will notify the proxy via a callback when the CPC reply comes back from the uima-as service. Synchronize the CPC code and force it to wait for the reply.