NCBC-395: Assign each client instance an identifer

Change-Id: Ib20248cb80a0a88e6de8c87c54f5176e85449f63
Reviewed-on: http://review.couchbase.org/33691
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>
Reviewed-by: Matt Ingenthron <matt@couchbase.com>

src/Enyim.Caching/IMemcachedClient.cs

@@ -57,5 +57,6 @@ public interface IMemcachedClient : IDisposable
 		ServerStats Stats(string type);
 
 		event Action<IMemcachedNode> NodeFailed;
+        Guid Identity { get; }
 	}
 }

src/Enyim.Caching/MemcachedClient.cs

@@ -88,6 +88,9 @@ public MemcachedClient(IServerPool pool, IMemcachedKeyTransformer keyTransformer
 			if (keyTransformer == null) throw new ArgumentNullException("keyTransformer");
 			if (transcoder == null) throw new ArgumentNullException("transcoder");
 
+		    Identity = Guid.NewGuid();
+            log.WarnFormat("Creating new client. CID: {0} {1}", Identity, GetType().Name);
+
 			this.performanceMonitor = performanceMonitor;
 			this.keyTransformer = keyTransformer;
 			this.transcoder = transcoder;
@@ -1082,7 +1085,10 @@ public void Dispose()
 		}
 
 		#endregion
-	}
+
+
+        public Guid Identity { get; protected set; }
+    }
 }
 
 #region [ License information          ]