Fixed two issues and a few typos (#260)

* fixed CommandClient.registerGuildPrefix and .onMessageReactionEvent

* followed @macdja38's suggestion

* fixed some typos

lib/command/CommandClient.js

@@ -169,7 +169,7 @@ class CommandClient extends Client {
     }
 
     onMessageReactionEvent(msg, emoji, userID) {
-        if(!this.ready || userID === this.user.id || !msg.content) {
+        if(!this.ready || userID === this.user.id || !(msg.content && msg.embeds && msg.attachments)) {
             return;
         }
 
@@ -206,7 +206,7 @@ class CommandClient extends Client {
     * @arg {String|Array} prefix The bot prefix. Can be either an array of prefixes or a single prefix. "@mention" will be automatically replaced with the bot's actual mention
     */
     registerGuildPrefix(guildID, prefix) {
-        if(this.preReady){
+        if(!this.preReady){
             this.guildPrefixes[guildID] = prefix;
         } else {
             if(Array.isArray(prefix)){

lib/rest/RequestHandler.js

@@ -7,7 +7,7 @@ const SequentialBucket = require("../util/SequentialBucket");
 const Zlib = require("zlib");
 
 /**
-* Handles APi requests
+* Handles API requests
 */
 class RequestHandler {
     constructor(client, forceQueueing) {

lib/structures/Channel.js

@@ -52,7 +52,7 @@ class Channel extends Base {
 
     /**
     * Create a message in a text channel
-    * Note: If you want to DM someone, the user ID is **not** the DM channel ID. use Client.getDMChanne() to get the DM channel ID for a user
+    * Note: If you want to DM someone, the user ID is **not** the DM channel ID. use Client.getDMChannel() to get the DM channel ID for a user
     * @arg {String | Object} content A string or object. If an object is passed:
     * @arg {String} content.content A content string
     * @arg {Boolean} [content.tts] Set the message TTS flag

lib/structures/GuildAuditLogEntry.js

@@ -11,7 +11,7 @@ const Invite = require("./Invite");
 * @prop {String?} reason The reason for the action
 * @prop {User} user The user that performed the action
 * @prop {String} targetID The ID of the action target
-* @prop {(Guild | GuildChannel | Member | Invite | Role | Object)?} target The ID of the action target
+* @prop {(Guild | GuildChannel | Member | Invite | Role | Object)?} target The object of the action target
 * If the item is not cached, this property will be null
 * If the action targets a guild, this could be a Guild object
 * If the action targets a guild channel, this could be a GuildChannel object

lib/structures/User.js

@@ -86,7 +86,7 @@ class User extends Base {
     }
 
     /**
-    * Create a relationship with the user
+    * Create a relationship with the user (user accounts only)
     * @arg {Boolean} [block=false] If true, block the user. Otherwise, add the user as a friend
     * @returns {Promise}
     */
@@ -95,7 +95,7 @@ class User extends Base {
     }
 
     /**
-    * Remove a relationship with the user
+    * Remove a relationship with the user (user accounts only)
     * @returns {Promise}
     */
     removeRelationship() {