More examples and tweaks

* Signal dispatch() method now uses own pid as default value
* SharedData now updates checksum cache on set()

examples/channels.php

@@ -0,0 +1,16 @@
+<?php
+
+require_once __DIR__."/../vendor/autoload.php";
+
+use NoccyLabs\Ipc\Interop\Channel\StreamChannel;
+
+// Create a pair of channels.
+[ $ch1, $ch2 ] = StreamChannel::createPair();
+
+// Send messages with send()
+$ch1->send([
+    'msg' => "Hello World"
+]);
+
+// Receive at the other end using receive()
+print_r($ch2->receive());