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/extras/ConfigDoc/HTMLXSLTProcessor.php

@@ -0,0 +1,91 @@
+<?php
+
+/**
+ * Decorator/extender XSLT processor specifically for HTML documents.
+ */
+class ConfigDoc_HTMLXSLTProcessor
+{
+
+    /**
+     * Instance of XSLTProcessor
+     */
+    protected $xsltProcessor;
+
+    public function __construct($proc = false)
+    {
+        if ($proc === false) $proc = new XSLTProcessor();
+        $this->xsltProcessor = $proc;
+    }
+
+    /**
+     * @note Allows a string $xsl filename to be passed
+     */
+    public function importStylesheet($xsl)
+    {
+        if (is_string($xsl)) {
+            $xsl_file = $xsl;
+            $xsl = new DOMDocument();
+            $xsl->load($xsl_file);
+        }
+        return $this->xsltProcessor->importStylesheet($xsl);
+    }
+
+    /**
+     * Transforms an XML file into compatible XHTML based on the stylesheet
+     * @param $xml XML DOM tree, or string filename
+     * @return string HTML output
+     * @todo Rename to transformToXHTML, as transformToHTML is misleading
+     */
+    public function transformToHTML($xml)
+    {
+        if (is_string($xml)) {
+            $dom = new DOMDocument();
+            $dom->load($xml);
+        } else {
+            $dom = $xml;
+        }
+        $out = $this->xsltProcessor->transformToXML($dom);
+
+        // fudges for HTML backwards compatibility
+        // assumes that document is XHTML
+        $out = str_replace('/>', ' />', $out); // <br /> not <br/>
+        $out = str_replace(' xmlns=""', '', $out); // rm unnecessary xmlns
+
+        if (class_exists('Tidy')) {
+            // cleanup output
+            $config = array(
+                'indent'        => true,
+                'output-xhtml'  => true,
+                'wrap'          => 80
+            );
+            $tidy = new Tidy;
+            $tidy->parseString($out, $config, 'utf8');
+            $tidy->cleanRepair();
+            $out = (string) $tidy;
+        }
+
+        return $out;
+    }
+
+    /**
+     * Bulk sets parameters for the XSL stylesheet
+     * @param array $options Associative array of options to set
+     */
+    public function setParameters($options)
+    {
+        foreach ($options as $name => $value) {
+            $this->xsltProcessor->setParameter('', $name, $value);
+        }
+    }
+
+    /**
+     * Forward any other calls to the XSLT processor
+     */
+    public function __call($name, $arguments)
+    {
+        call_user_func_array(array($this->xsltProcessor, $name), $arguments);
+    }
+
+}
+
+// vim: et sw=4 sts=4