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

Fixes #472

lib/Minify/LessCssSource.php

@@ -0,0 +1,107 @@
+<?php
+
+class Minify_LessCssSource extends Minify_Source {
+    /**
+     * @var Minify_CacheInterface
+     */
+    private $cache;
+
+    /**
+     * Parsed lessphp cache object
+     *
+     * @var array
+     */
+    private $parsed;
+
+    /**
+     * @inheritdoc
+     */
+    public function __construct(array $spec, Minify_CacheInterface $cache) {
+        parent::__construct($spec);
+
+        $this->cache = $cache;
+    }
+
+    /**
+     * Get last modified of all parsed files
+     *
+     * @return int
+     */
+    public function getLastModified() {
+        $cache = $this->getCache();
+
+        $lastModified = 0;
+        foreach ($cache['files'] as $mtime) {
+            $lastModified = max($lastModified, $mtime);
+
+        }
+        return $lastModified;
+    }
+
+    /**
+     * Get content
+     *
+     * @return string
+     */
+    public function getContent() {
+        $cache = $this->getCache();
+
+        return $cache['compiled'];
+    }
+
+    /**
+     * Get lessphp cache object
+     *
+     * @return array
+     */
+    private function getCache() {
+        // cache for single run
+        // so that getLastModified and getContent in single request do not add additional cache roundtrips (i.e memcache)
+        if (isset($this->parsed)) {
+            return $this->parsed;
+        }
+
+        // check from cache first
+        $cache = null;
+        $cacheId = $this->getCacheId();
+        if ($this->cache->isValid($cacheId, 0)) {
+            if ($cache = $this->cache->fetch($cacheId)) {
+                $cache = unserialize($cache);
+            }
+        }
+
+        $less = $this->getCompiler();
+        $input = $cache ? $cache : $this->filepath;
+        $cache = $less->cachedCompile($input);
+
+        if (!is_array($input) || $cache['updated'] > $input['updated']) {
+            $this->cache->store($cacheId, serialize($cache));
+        }
+
+        return $this->parsed = $cache;
+    }
+
+    /**
+     * Make a unique cache id for for this source.
+     *
+     * @param string $prefix
+     *
+     * @return string
+     */
+    private function getCacheId($prefix = 'minify') {
+        $md5 = md5($this->filepath);
+        return "{$prefix}_less_{$md5}";
+    }
+
+    /**
+     * Get instance of less compiler
+     *
+     * @return lessc
+     */
+    private function getCompiler() {
+        $less = new lessc();
+        // do not spend CPU time letting less doing minify
+        $less->setPreserveComments(true);
+        return $less;
+    }
+}