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

ssl_session_cache none

avoid recursive loop

expires modified

$uid_got and $uid_set may used at any time

$hostname variable

escape 0x00-0x1f, ", and \ in access log variables

*) host in request line has priority
*) allow several Host headers
*) validate host

style fixes