Add /cycle command (a.k.a. /rejoin)

Closes #1436

client/index.html

@@ -785,6 +785,19 @@
 							</div>
 						</div>
 
+						<div class="help-item">
+							<div class="subject">
+								<code>/rejoin</code>
+							</div>
+							<div class="description">
+								<p>
+									Leave and immediately rejoin the current channel. Useful to
+									quickly get op from ChanServ in an empty channel, for example.
+								</p>
+								<p>Alias: <code>/cycle</code></p>
+							</div>
+						</div>
+
 						<div class="help-item">
 							<div class="subject">
 								<code>/query nick</code>

client/js/constants.js

@@ -28,6 +28,7 @@ const commands = [
 	"/collapse",
 	"/connect",
 	"/ctcp",
+	"/cycle",
 	"/deop",
 	"/devoice",
 	"/disconnect",
@@ -46,6 +47,7 @@ const commands = [
 	"/query",
 	"/quit",
 	"/raw",
+	"/rejoin",
 	"/say",
 	"/send",
 	"/server",

src/client.js

@@ -41,6 +41,7 @@ var inputs = [
 	"ctcp",
 	"msg",
 	"part",
+	"rejoin",
 	"action",
 	"away",
 	"connect",

src/plugins/inputs/rejoin.js

@@ -0,0 +1,21 @@
+"use strict";
+
+var Msg = require("../../models/msg");
+var Chan = require("../../models/chan");
+
+exports.commands = ["cycle", "rejoin"];
+
+exports.input = function(network, chan) {
+	if (chan.type !== Chan.Type.CHANNEL) {
+		chan.pushMessage(this, new Msg({
+			type: Msg.Type.ERROR,
+			text: "You can only rejoin channels."
+		}));
+		return;
+	}
+
+	network.irc.part(chan.name, "Rejoining");
+	network.irc.join(chan.name);
+
+	return true;
+};