Refs leafo#224 - add PHP version check

Author: robocoder

scss.inc.php

@@ -1,4 +1,8 @@
 <?php
+if (version_compare(PHP_VERSION, '5.3') < 0) {
+    die('Requires PHP 5.3 or above');
+}
+
 if ( ! class_exists('scssc')) {
     include_once __DIR__ . '/src/Colors.php';
     include_once __DIR__ . '/src/Compiler.php';