Added packaging script

util/package.php

+<?php
+
+$platforms = [
+	"chrome",
+	"firefox"
+];
+$root = preg_replace('/\/[^\/]+$/','',dirname(__FILE__));
+
+foreach ($platforms as $platform) {
+	$manifest = JSON_decode(file_get_contents("{$root}/build/{$platform}/manifest.json"), true);
+	$version = $manifest["version"];
+	`cd {$root}/build/{$platform}; tar czf {$root}/AlwaysKillSticky-{$platform}-{$version}.tar.gz *`;
+}
+
+?>