Allow log level to be specified in constructor

It can still be set using `lmq.log_level(...)`, but this can be slightly
more convenient -- and without this log messages in the constructor are
completely useless.

lokimq/lokimq.cpp

@@ -203,9 +203,10 @@ LokiMQ::LokiMQ(
         std::string privkey_,
         bool service_node,
         SNRemoteAddress lookup,
-        Logger logger)
+        Logger logger,
+        LogLevel level)
     : object_id{next_id++}, pubkey{std::move(pubkey_)}, privkey{std::move(privkey_)}, local_service_node{service_node},
-        sn_lookup{std::move(lookup)}, logger{std::move(logger)}
+        sn_lookup{std::move(lookup)}, log_lvl{level}, logger{std::move(logger)}
 {
 
     LMQ_TRACE("Constructing listening LokiMQ, id=", object_id, ", this=", this);

lokimq/lokimq.h

@@ -627,20 +627,26 @@ public:
      *
      * @param log a function or callable object that writes a log message.  If omitted then all log
      * messages are suppressed.
+     *
+     * @param level the initial log level; defaults to warn.  The log level can be changed later by
+     * calling log_level(...).
      */
     LokiMQ( std::string pubkey,
             std::string privkey,
             bool service_node,
             SNRemoteAddress sn_lookup,
-            Logger logger = [](LogLevel, const char*, int, std::string) { });
+            Logger logger = [](LogLevel, const char*, int, std::string) { },
+            LogLevel level = LogLevel::warn);
 
     /**
-     * Simplified LokiMQ constructor for a simple listener without any SN connection/authentication
-     * capabilities.  This treats all remotes as "basic", non-service node connections for command
-     * authentication purposes.
+     * Simplified LokiMQ constructor for a non-listening client or simple listener without any
+     * outgoing SN connection lookup capabilities.  The LokiMQ object will not be able to establish
+     * new connections (including reconnections) to service nodes by pubkey.
      */
-    explicit LokiMQ(Logger logger = [](LogLevel, const char*, int, std::string) { })
-        : LokiMQ("", "", false, [](auto) { return ""s; /*no peer lookups*/ }, std::move(logger)) {}
+    explicit LokiMQ(
+            Logger logger = [](LogLevel, const char*, int, std::string) { },
+            LogLevel level = LogLevel::warn)
+        : LokiMQ("", "", false, [](auto) { return ""s; /*no peer lookups*/ }, std::move(logger), level) {}
 
     /**
      * Destructor; instructs the proxy to quit.  The proxy tells all workers to quit, waits for them