-* added ob_httpetaghandler() (has major limitations compared to http_cache_etag())
-* smarter ob handling in http_cache_etag() - used buffers will be fetched, freed
- and piped through again, so that everything passes the etag ob handler
-* added static final HTTPi class (PHP5) providing fairly every function as static method
-* added HTTPi_Response class (PHP5)
-* renamed http_content_type() and http_content_disposition() to http_send_*