handle "/../" case more reliably

fix segfault when a header starts with "\rX"
and logging is set to info or debug level

fix error when response parsed by sub filter, then by SSI filter
and some response parts are output as file buffers

fix bug when inactive subrequest is truncated,
if output_buffers are less than subrequest size

avoid recursive loop

reset looked at match

fix segfault

fix segfault if empty stub block is used second time