reset looked at match

fix segfault if empty stub block is used second time

upstream parse_header fix and optimization,
fix fastcgi_catch_stderr segfault merged in r1524:

*) return NGX_HTTP_UPSTREAM_INVALID_HEADER for invalid status
*) return NGX_ERROR instead of NGX_HTTP_INTERNAL_SERVER_ERROR
   in u->parse_header()
*) return NGX_HTTP_UPSTREAM_INVALID_HEADER instead of NGX_HTTP_BAD_GATEWAY
   to go to a next upstream on invalid_header condition
*) now ngx_conf_set_str_array_slot() tests NGX_CONF_UNSET_PTR
   this fixes fastcgi_catch_stderr segfault
*) ngx_http_upstream_hide_headers_hash()
*) proxy/fastcgi pass_header/hide_header use
   ngx_http_upstream_hide_headers_hash()

use usec and pid as start value

omit unnecessary test, because NGX_ERROR == -1,
but r->headers_out.last_modified_time != -1 at this point

If-Range support

set status in correct place

*) copy protocol value when large request line is copied,
   this fixes error "fastcgi: the request record is too big"
*) log how big fastcgi record