[3.1.0] More PHP4->PHP5 conversions, notably reference removal of most methods that return objects

- Removed HTMLPurifier_Error
- Documentation updates
- Removed more copy() methods in favor of clone
- HTMLPurifier::getInstance() to HTMLPurifier::instance()
- Fix InterchangeBuilder to use HTMLPURIFIER_PREFIX

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1689 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier.php

@@ -207,9 +207,10 @@ class HTMLPurifier
     /**
      * Singleton for enforcing just one HTML Purifier in your system
      * @param $prototype Optional prototype HTMLPurifier instance to
-     *                   overload singleton with.
+     *                   overload singleton with, or HTMLPurifier_Config
+     *                   instance to configure the generated version with.
      */
-    public static function getInstance($prototype = null) {
+    public static function instance($prototype = null) {
         if (!self::$instance || $prototype) {
             if ($prototype instanceof HTMLPurifier) {
                 self::$instance = $prototype;
@@ -222,4 +223,11 @@ class HTMLPurifier
         return self::$instance;
     }
     
+    /**
+     * @note Backwards compatibility, see instance()
+     */
+    public static function getInstance($prototype = null) {
+        return HTMLPurifier::instance($prototype);
+    }
+    
 }