minor cleanup

core/message.js

@@ -351,13 +351,13 @@ Message.prototype.persist = function(cb) {
 		return cb(new Error('Cannot persist invalid message!'));
 	}
 
-	let self = this;
+	const self = this;
 	
 	async.series(
 		[
 			function beginTransaction(callback) {
 				Message.startTransaction(err => {
-					callback(err);
+					return callback(err);
 				});
 			},
 			function storeMessage(callback) {
@@ -375,19 +375,19 @@ Message.prototype.persist = function(cb) {
 					`INSERT INTO message (area_tag, message_uuid, reply_to_message_id, to_user_name, from_user_name, subject, message, modified_timestamp)
 					VALUES (?, ?, ?, ?, ?, ?, ?, ?);`, 
 					[ self.areaTag, self.uuid, self.replyToMsgId, self.toUserName, self.fromUserName, self.subject, self.message, self.getMessageTimestampString(msgTimestamp) ],
-					function inserted(err) {	//	use for this scope
+					function inserted(err) {	//	use non-arrow function for 'this' scope
 						if(!err) {
 							self.messageId = this.lastID;
 						}
 
-						callback(err);
+						return callback(err);
 					}
 				);
 			},
 			function storeMeta(callback) {
 				if(!self.meta) {
-					callback(null);
-				} else {
+					return callback(null);
+				}
 				/*
 					Example of self.meta:
 					
@@ -412,16 +412,15 @@ Message.prototype.persist = function(cb) {
 				}, err => {
 					callback(err);
 				});					
-				}
 			},
 			function storeHashTags(callback) {
 				//	:TODO: hash tag support
-				callback(null);
+				return callback(null);
 			}
 		],
 		err => {
 			Message.endTransaction(err, transErr => {
-				cb(err ? err : transErr, self.messageId);
+				return cb(err ? err : transErr, self.messageId);
 			});
 		}
 	);

core/message_area.js

@@ -560,10 +560,10 @@ function persistMessage(message, cb) {
 	async.series(
 		[
 			function persistMessageToDisc(callback) {
-				message.persist(callback);
+				return message.persist(callback);
 			},
 			function recordToMessageNetworks(callback) {
-				msgNetRecord(message, callback);
+				return msgNetRecord(message, callback);
 			}			
 		],
 		cb