Replace existing autoloader with Composer-supplied

- Move Friendica namespace to `src`
- Move required `ezyang/htmlpurifier` to vendor
- Remove existing static autoloader
- Change boot.php reference to the autoloader

vendor/ezyang/htmlpurifier/library/HTMLPurifier/Printer/CSSDefinition.php

@@ -0,0 +1,44 @@
+<?php
+
+class HTMLPurifier_Printer_CSSDefinition extends HTMLPurifier_Printer
+{
+    /**
+     * @type HTMLPurifier_CSSDefinition
+     */
+    protected $def;
+
+    /**
+     * @param HTMLPurifier_Config $config
+     * @return string
+     */
+    public function render($config)
+    {
+        $this->def = $config->getCSSDefinition();
+        $ret = '';
+
+        $ret .= $this->start('div', array('class' => 'HTMLPurifier_Printer'));
+        $ret .= $this->start('table');
+
+        $ret .= $this->element('caption', 'Properties ($info)');
+
+        $ret .= $this->start('thead');
+        $ret .= $this->start('tr');
+        $ret .= $this->element('th', 'Property', array('class' => 'heavy'));
+        $ret .= $this->element('th', 'Definition', array('class' => 'heavy', 'style' => 'width:auto;'));
+        $ret .= $this->end('tr');
+        $ret .= $this->end('thead');
+
+        ksort($this->def->info);
+        foreach ($this->def->info as $property => $obj) {
+            $name = $this->getClass($obj, 'AttrDef_');
+            $ret .= $this->row($property, $name);
+        }
+
+        $ret .= $this->end('table');
+        $ret .= $this->end('div');
+
+        return $ret;
+    }
+}
+
+// vim: et sw=4 sts=4