fixes in shared memory:

only allow server to create and initialize shared memory,
client will report failure
intercept signals to cleanup shared memory in standalone app, thanks to
Roland Philippsen.

examples/SharedMemory/SharedMemoryCommon.h

@@ -12,6 +12,7 @@ public:
 	}
 
 	virtual bool wantsTermination()=0;
+    virtual bool isConnected()=0;
 };
 #endif//