fixes #2092 redesigned handling of return to gallery after photo edit

* instead of using the provided cat_id in the URL parameters, registers the "context" of the last 10 photos viewed. Be it an album, a search, a tag...
* maybe not the cleanest way to do it (because we do not rebuild the url string) but simple and straightforward

include/section_init.inc.php

@@ -59,6 +59,8 @@ if ( strncmp($page['root_path'], './', 2) == 0 )
   $page['root_path'] = substr($page['root_path'], 2);
 }
 
+$page['section_url'] = $rewritten;
+
 // deleting first "/" if displayed
 $tokens = explode('/', ltrim($rewritten, '/') );
 // $tokens = array(