Added multichannels and a simple channel-based bus

examples/bus.php

@@ -0,0 +1,28 @@
+<?php
+
+require_once __DIR__."/../vendor/autoload.php";
+
+use NoccyLabs\Ipc\Interop\Bus\Master;
+
+
+$master = new Master();
+
+$client1 = $master->createClient();
+$client1->addListener(function ($msg) use ($client1) {
+    printf("channel1: %s\n", json_encode($msg));
+    $client1->call("/channel2/hello", "channel1")->then(function ($ret) {
+        printf("channel1: %s\n", $ret);
+    });
+});
+$client2 = $master->createClient();
+$client2->addListener(function ($msg) {
+    printf("channel2: %s\n", json_encode($msg));
+});
+$client2->export("/channel2/hello", function ($name) {
+    return sprintf("Hello, %s", $name);
+});
+
+$client1->send("hello world");
+for ($n = 0; $n < 10; $n++) {
+    sleep(1);
+}