Reduce log verbosity.

Creators of ServerSession all log the reason for creating a session.

Use "Session0.n" as the ID of non-pooled sessions.

Author: bgrainger

src/MySqlConnector/Core/ServerSession.cs

@@ -33,15 +33,13 @@ public ServerSession(ConnectionPool pool, int poolGeneration, int id)
 		{
 			m_lock = new object();
 			m_payloadCache = new ArraySegmentHolder<byte>();
-			Id = id.ToString();
-			if (pool != null)
-				Id = pool.Id + "." + Id;
+			Id = (pool?.Id ?? 0) + "." + id;
 			CreatedUtc = DateTime.UtcNow;
 			Pool = pool;
 			PoolGeneration = poolGeneration;
 			HostName = "";
 			m_logArguments = new object[] { "Session{0}".FormatInvariant(Id), null };
-			Log.Info("{0} created new session", m_logArguments);
+			Log.Debug("{0} created new session", m_logArguments);
 		}
 
 		public string Id { get; }

src/MySqlConnector/MySql.Data.MySqlClient/MySqlConnection.cs

@@ -372,6 +372,7 @@ private async Task<ServerSession> CreateSessionAsync(IOBehavior ioBehavior, Canc
 							RandomLoadBalancer.Instance : FailOverLoadBalancer.Instance;
 
 						var session = new ServerSession();
+						Log.Info("Created new non-pooled Session{0}", session.Id);
 						await session.ConnectAsync(m_connectionSettings, loadBalancer, ioBehavior, linkedSource.Token).ConfigureAwait(false);
 						return session;
 					}