TOC arrow with simple transparency

This patch exchanges the images for the TOC arrow from
PNG with alpha channel to GIF with transparent background.
This is done because the IE doesn't cope with transparent
PNG images very well. Shame on you Microsoft.

darcs-hash:20050606163659-7ef76-8a5d482ec2c73b87f4ece0b1226933cbd1ca7d60.gz

inc/parser/xhtml.php

@@ -73,8 +73,8 @@ class Doku_Renderer_xhtml extends Doku_Renderer {
 /*      The (+/-) version will work too but needs some CSS tweaking to look fine */
 /*      $this->doc .= ' <script type="text/javascript">showTocToggle("+","-")';*/
         $this->doc .=  '<script type="text/javascript">showTocToggle(';
-        $this->doc .=    '\'<img src="'.DOKU_BASE.'lib/images/arrow_down.png">\',';
-        $this->doc .=    '\'<img src="'.DOKU_BASE.'lib/images/arrow_up.png">\')';
+        $this->doc .=    '\'<img src="'.DOKU_BASE.'lib/images/arrow_down.gif">\',';
+        $this->doc .=    '\'<img src="'.DOKU_BASE.'lib/images/arrow_up.gif">\')';
         $this->doc .=  '</script>';
         $this->doc .= $lang['toc'];
         $this->doc .= '</div>'.DOKU_LF;