header support for renderer plugins

Renderer plugins now can store HTTP header information in 'format <mode>' which
will be used to send their output. Also fixes a problem with loading cache files.

darcs-hash:20071016185626-7ad00-c0e18a90b310daf0d3a3c01d7a73f3524ced803d.gz

inc/actions.php

@@ -408,7 +408,11 @@ function act_export($act){
   // try to run renderer
   $mode = substr($act,7);
   $text = p_cached_output(wikiFN($ID,$REV), $mode);
+  $headers = p_get_metadata($ID,"format $mode");
   if(!is_null($text)){
+    if(is_array($headers)) foreach($headers as $key => $val){
+        header("$key: $val");
+    }
     print $text;
     exit;
   }

inc/parserutils.php

@@ -147,7 +147,7 @@ function p_cached_output($file, $format='xhtml', $id='') {
 
   $cache = new cache_renderer($id, $file, $format);
   if ($cache->useCache()) {
-    $parsed = $cache->retrieveCache();
+    $parsed = $cache->retrieveCache(false);
     if($conf['allowdebug'] && $format=='xhtml') $parsed .= "\n<!-- cachefile {$cache->cache} used -->\n";
   } else {
     $parsed = p_render($format, p_cached_instructions($file,false,$id), $info);