Add Connection helper class

This is intended to make querying a "server" easier by wrapping common
functionality into one class.

maxscale-system-test/maxscales.h

@@ -156,6 +156,14 @@ public:
         return open_conn(rwsplit_port[m], IP[m], user_name, password, ssl);
     }
 
+    /**
+     * Get a readwritesplit Connection
+     */
+    Connection rwsplit(int m = 0)
+    {
+        return Connection(IP[m], rwsplit_port[m], user_name, password, "test", ssl);
+    }
+
     /**
      * @brief OpenReadMasterConn    Opens new connections to ReadConn master and returns MYSQL struct
      * To close connection mysql_close() have to be called
@@ -167,6 +175,14 @@ public:
                          password, ssl);
     }
 
+    /**
+     * Get a readconnroute master Connection
+     */
+    Connection readconn_master(int m = 0)
+    {
+        return Connection(IP[m], readconn_master_port[m], user_name, password, "test", ssl);
+    }
+
     /**
      * @brief OpenReadSlaveConn    Opens new connections to ReadConn slave and returns MYSQL struct
      * To close connection mysql_close() have to be called
@@ -178,6 +194,14 @@ public:
                          password, ssl);
     }
 
+    /**
+     * Get a readconnroute slave Connection
+     */
+    Connection readconn_slave(int m = 0)
+    {
+        return Connection(IP[m], readconn_slave_port[m], user_name, password, "test", ssl);
+    }
+
     /**
      * @brief CloseRWSplit Closes RWplit connections stored in maxscales->conn_rwsplit[0]
      */