Add MessageCreate handler, set up Message class and add ability to Cache messages

src/structures/DMChannel.js

@@ -2,10 +2,26 @@
 
 const Channel = require('./Channel');
 const User = require('./User');
+const TextChannelDataStore = require('./datastore/TextChannelDataStore');
 
 class DMChannel extends Channel{
 	constructor(client, data) {
 		super(client, data);
+		this.store = new TextChannelDataStore();
+	}
+
+	_cacheMessage(message) {
+		let maxSize = this.client.options.max_message_cache;
+		if (maxSize === 0) {
+			// saves on performance
+			return;
+		}
+
+		let storeKeys = Object.keys(this.store);
+		if (storeKeys.length >= maxSize) {
+			this.store.remove(storeKeys[0]);
+			this.store.add('messages', message);
+		}
 	}
 
 	setup(data) {