Merge r1587036, r1587040, r1587053, r1587654 from trunk:

  *) mod_proxy_wstunnel: Don't pool backend websockets connections,
     because we need to handshake every time. PR 55890.
     [Eric Covener]



actually remove mod_reqtimeout, since the util_filter functions involved
only manipulate c->input_filters no matter what we pass. We need to make
copies of c->input_filters after, not before, it skips over reqtimeout.

Note: reqtimeout doesn't really interfere today with normal operation,
but this is misleading/confusing when dealing with other
wstunnel issues.



cleanup wstunnel error handling

Submitted By: covener, ylavic, Edward Lu
Commited By: covener



followup to r1587036.

if backend->close is set too early, proxy_util.c will close it right 
away and then blow away the field.

Submitted by: covener
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1588495 13f79535-47bb-0310-9956-ffa450edef68