- bug-fix for lookup of hosts defined via host_node_map (see http://openacs.org/forums/message-view?message_id=4106578)
- fix bug with redirects and host-node maps (see http://openacs.org/forums/message-post?parent_id=4106585)
- added argument "-passing_style" to search::content_filter
   to make explicit whether data contains content or a file name.
   Previously, text/* meant automatically passing-style string,
   leading to missing results when plain files were added
   to the content repository
- added filter for text/plain
- fixed filter for text/html
- further clean up