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/ConfigSchema/ValidatorAtom.php

@@ -0,0 +1,130 @@
+<?php
+
+/**
+ * Fluent interface for validating the contents of member variables.
+ * This should be immutable. See HTMLPurifier_ConfigSchema_Validator for
+ * use-cases. We name this an 'atom' because it's ONLY for validations that
+ * are independent and usually scalar.
+ */
+class HTMLPurifier_ConfigSchema_ValidatorAtom
+{
+    /**
+     * @type string
+     */
+    protected $context;
+
+    /**
+     * @type object
+     */
+    protected $obj;
+
+    /**
+     * @type string
+     */
+    protected $member;
+
+    /**
+     * @type mixed
+     */
+    protected $contents;
+
+    public function __construct($context, $obj, $member)
+    {
+        $this->context = $context;
+        $this->obj = $obj;
+        $this->member = $member;
+        $this->contents =& $obj->$member;
+    }
+
+    /**
+     * @return HTMLPurifier_ConfigSchema_ValidatorAtom
+     */
+    public function assertIsString()
+    {
+        if (!is_string($this->contents)) {
+            $this->error('must be a string');
+        }
+        return $this;
+    }
+
+    /**
+     * @return HTMLPurifier_ConfigSchema_ValidatorAtom
+     */
+    public function assertIsBool()
+    {
+        if (!is_bool($this->contents)) {
+            $this->error('must be a boolean');
+        }
+        return $this;
+    }
+
+    /**
+     * @return HTMLPurifier_ConfigSchema_ValidatorAtom
+     */
+    public function assertIsArray()
+    {
+        if (!is_array($this->contents)) {
+            $this->error('must be an array');
+        }
+        return $this;
+    }
+
+    /**
+     * @return HTMLPurifier_ConfigSchema_ValidatorAtom
+     */
+    public function assertNotNull()
+    {
+        if ($this->contents === null) {
+            $this->error('must not be null');
+        }
+        return $this;
+    }
+
+    /**
+     * @return HTMLPurifier_ConfigSchema_ValidatorAtom
+     */
+    public function assertAlnum()
+    {
+        $this->assertIsString();
+        if (!ctype_alnum($this->contents)) {
+            $this->error('must be alphanumeric');
+        }
+        return $this;
+    }
+
+    /**
+     * @return HTMLPurifier_ConfigSchema_ValidatorAtom
+     */
+    public function assertNotEmpty()
+    {
+        if (empty($this->contents)) {
+            $this->error('must not be empty');
+        }
+        return $this;
+    }
+
+    /**
+     * @return HTMLPurifier_ConfigSchema_ValidatorAtom
+     */
+    public function assertIsLookup()
+    {
+        $this->assertIsArray();
+        foreach ($this->contents as $v) {
+            if ($v !== true) {
+                $this->error('must be a lookup array');
+            }
+        }
+        return $this;
+    }
+
+    /**
+     * @param string $msg
+     * @throws HTMLPurifier_ConfigSchema_Exception
+     */
+    protected function error($msg)
+    {
+        throw new HTMLPurifier_ConfigSchema_Exception(ucfirst($this->member) . ' in ' . $this->context . ' ' . $msg);
+    }
+}
+
+// vim: et sw=4 sts=4