Add runtime schemarouter reconfiguration

The schemarouter now also uses versioned configurations implemented by
shared pointers to configuration objects. Moved all the configuration
management into the Config class. Removed router options from
schemarouter.

server/modules/routing/schemarouter/schemarouter.hh

@@ -48,17 +48,17 @@ struct Config
     std::set<std::string> ignored_dbs;      /**< Set of ignored databases */
     SERVER*           preferred_server;     /**< Server to prefer in conflict situations */
 
-    Config():
-        refresh_min_interval(0.0),
-        refresh_databases(false),
-        debug(false),
-        ignore_regex(NULL),
-        ignore_match_data(NULL),
-        preferred_server(NULL)
+    Config(MXS_CONFIG_PARAMETER* conf);
+
+    ~Config()
     {
+        pcre2_match_data_free(ignore_match_data);
+        pcre2_code_free(ignore_regex);
     }
 };
 
+typedef std::shared_ptr<Config> SConfig;
+
 /**
  * Router statistics
  */