Remove dependency on Sass

- Convert *.sass files to vanilla CSS
- Start using CSS variables
- Add PHP minifier

libs/minify/src/Exceptions/FileImportException.php

@@ -0,0 +1,21 @@
+<?php
+/**
+ * File Import Exception
+ *
+ * Please report bugs on https://github.com/matthiasmullie/minify/issues
+ *
+ * @author Matthias Mullie <minify@mullie.eu>
+ * @copyright Copyright (c) 2012, Matthias Mullie. All rights reserved
+ * @license MIT License
+ */
+namespace MatthiasMullie\Minify\Exceptions;
+
+/**
+ * File Import Exception Class
+ *
+ * @package Minify\Exception
+ * @author Matthias Mullie <minify@mullie.eu>
+ */
+class FileImportException extends BasicException
+{
+}