conn: store client and server protocol info

Store client and server protocol version and features in connection
object, similar to go-tarantool [1]. Before the patch, we stored only
products: minimal protocol version of server and client and the list
of features supported both by client and server.

1. tarantool/go-tarantool#226

Part of #267

Author: DifferentialOrange

tarantool/connection.py

@@ -1044,10 +1044,11 @@ def handshake(self):
         if greeting.protocol != "Binary":
             raise NetworkError("Unsupported protocol: " + greeting.protocol)
         self.version_id = greeting.version_id
-        if self.version_id >= version_id(2, 10, 0):
-            self._check_features()
         self.uuid = greeting.uuid
         self._salt = greeting.salt
+
+        self._check_features()
+
         if self.user:
             self.authenticate(self.user, self.password)
 
@@ -2057,21 +2058,27 @@ def _check_features(self):
             :exc:`~tarantool.error.SslError`
         """
 
-        try:
-            request = RequestProtocolVersion(self,
-                                             CONNECTOR_IPROTO_VERSION,
-                                             CONNECTOR_FEATURES)
-            response = self._send_request(request)
-            server_protocol_version = response.protocol_version
-            server_features = response.features
-            server_auth_type = response.auth_type
-        except DatabaseError as exc:
-            if exc.code == ER_UNKNOWN_REQUEST_TYPE:
-                server_protocol_version = None
-                server_features = []
-                server_auth_type = None
-            else:
-                raise exc
+        server_protocol_version = None
+        server_features = []
+        server_auth_type = None
+
+        if self.version_id >= version_id(2, 10, 0):
+            try:
+                request = RequestProtocolVersion(self,
+                                                 CONNECTOR_IPROTO_VERSION,
+                                                 CONNECTOR_FEATURES)
+                response = self._send_request(request)
+                server_protocol_version = response.protocol_version
+                server_features = response.features
+                server_auth_type = response.auth_type
+            except DatabaseError as exc:
+                if exc.code != ER_UNKNOWN_REQUEST_TYPE:
+                    raise exc
+
+        self.client_protocol_version = CONNECTOR_IPROTO_VERSION
+        self.client_features = copy(CONNECTOR_FEATURES)
+        self.server_protocol_version = server_protocol_version
+        self.server_features = copy(server_features)
 
         if server_protocol_version is not None:
             self._protocol_version = min(server_protocol_version,