Make BUrlProtocolAsynchronousListener inherit BUrlProtocolListener

* With so long class names, there's no way I'm going to follow the 64
char limit on commit headlines.
 * The class share the same API, so having them separate is not very
useful.
 * This makes it possible to use the same listener in either synchronous
or asycnhronous mode (or both, for different requests)

headers/os/net/UrlProtocolAsynchronousListener.h

@@ -11,26 +11,13 @@
 #include <UrlProtocolDispatchingListener.h>
 
 
-class BUrlProtocolAsynchronousListener : public BHandler {
+class BUrlProtocolAsynchronousListener : public BHandler,
+	public BUrlProtocolListener {
 public:
 								BUrlProtocolAsynchronousListener(
 									bool transparent = false);
 	virtual						~BUrlProtocolAsynchronousListener();
 
-	virtual	void				ConnectionOpened(BUrlRequest* caller);
-	virtual void				HostnameResolved(BUrlRequest* caller,
-									const char* ip);
-	virtual void				ResponseStarted(BUrlRequest* caller);
-	virtual void				HeadersReceived(BUrlRequest* caller);
-	virtual void				DataReceived(BUrlRequest* caller,
-									const char* data, ssize_t size);
-	virtual	void				DownloadProgress(BUrlRequest* caller,
-									ssize_t bytesReceived, ssize_t bytesTotal);
-	virtual void				UploadProgress(BUrlRequest* caller,
-									ssize_t bytesSent, ssize_t bytesTotal);
-	virtual void				RequestCompleted(BUrlRequest* caller,
-									bool success);
-									
 	// Synchronous listener access
 			BUrlProtocolListener* SynchronousListener();