Mass 'ab' backports of:

Mass 'ab' backports of:

==================
r390504,i r390511, r390519, r394765, r395228, r396300, r413861 | colm

Give users the ability to set the window size for apache bench runs. Useful
for benchmarking largefile downloads.

  * Add siege-like behaviour to ApacheBench; output the results, as they have
    accrued so far, when the user interrupts with ctrl-c. As the signal handler
    is non-reentrant, we don't need volatiles, and the operations all look
    signal-safe.

  * Update the base version, since handling a signal differently is an external
    API change of sorts.

  * set the LastChangedRevision svn property, as ab.c has $Rev $ embedded, so
    it really should be.

when compiling statistics, only interate accross requests which occured.

A keepalive response need not neccessarily have included any content-length
header, handle this case properly for 304 responses. PR39789

==================
r516175 | trawick

ab: Add -r option to continue after socket receive errors.

Submitted by: Filip Hanik <devlist hanik.com>
Reviewed by: trawick

==================
r541138 | sctemme

Explain that POST data should be sent as the correct MIME type.
Submitted by Vincent Bray noodlet at gmail dot com,
edited and reviewed by sctemme

==================
r655214 | fielding

Overhaul ab.c stats collection and reporting to avoid integer
truncation and time divisions within the test loop, retain
native time resolution until output, remove unused data,
avoid structure copies, consistently round milliseconds, and
generally avoid losing accuracy of calculation due to type casts.

Incidentally fixes output bug on gnuplot (seconds were being
output as microseconds).  It would make more sense to output
gnuplot stats as microseconds after the start of test, but
this change returns us to consistency with pre-apr versions of ab.

PR: 44878, 44931.

==================
r655637 | fielding

Don't stop sending a request if EAGAIN is returned, which will only
happen if both the write and subsequent wait are returning EAGAIN,
and count posted bytes correctly when the initial write of a request
is not complete.

PR 10038, 38861, 39679
Submitted by: Patrick McManus <mcmanus datapower.com> (in 2003)
              Stefan Fleiter <stefan.fleiter web.de>  (in 2006)
              and Davanum Srinivas (in 2006).  Committed patch
              contains parts of all three, tweaked by Roy (2008).

==================
r655654 | fielding

Improve client performance by clearing connection pool instead
of destroying it.

PR 40054
Submitted by: Brad Roberts <braddr puremagic.com>

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@660576 13f79535-47bb-0310-9956-ffa450edef68