Collapse "min" into project root and get unit tests working.

Fixes #472

lib/Minify/Cache/Null.php

@@ -0,0 +1,66 @@
+<?php
+
+/**
+ * Class Minify_Cache_Null
+ *
+ * If this is used, Minify will not use a cache and, for each 200 response, will
+ * need to recombine files, minify and encode the output.
+ *
+ * @package Minify
+ */
+class Minify_Cache_Null implements Minify_CacheInterface {
+    /**
+     * Write data to cache.
+     *
+     * @param string $id cache id (e.g. a filename)
+     * @param string $data
+     *
+     * @return bool success
+     */
+    public function store($id, $data)
+    {
+    }
+
+    /**
+     * Get the size of a cache entry
+     *
+     * @param string $id cache id (e.g. a filename)
+     *
+     * @return int size in bytes
+     */
+    public function getSize($id)
+    {
+    }
+
+    /**
+     * Does a valid cache entry exist?
+     *
+     * @param string $id       cache id (e.g. a filename)
+     * @param int    $srcMtime mtime of the original source file(s)
+     *
+     * @return bool exists
+     */
+    public function isValid($id, $srcMtime)
+    {
+    }
+
+    /**
+     * Send the cached content to output
+     *
+     * @param string $id cache id (e.g. a filename)
+     */
+    public function display($id)
+    {
+    }
+
+    /**
+     * Fetch the cached content
+     *
+     * @param string $id cache id (e.g. a filename)
+     *
+     * @return string
+     */
+    public function fetch($id)
+    {
+    }
+}