Hello!

Pipelining patch v3 attached. The main change is moving
Curl_addHandleToSendOrPendPipeline(), Curl_checkPendPipeline(),
Curl_moveHandleFromSendToRecvPipeline() and Curl_isHandleAtHead() from
url.c to multi.c. It is possible to move Curl_addHandleToPipeline() to
multi.c also, but I think it is better to leave it at the same place
as Curl_removeHandleFromPipeline().

Also IsPipeliningEnabled() function is no longer static since it is
now used in multi.c. And MAX_PIPELINE_LENGTH is now defined in
urldata.h.

All tests are passed. And torture test 530 is also passed!

Now I plan to try some real world usage with pipelining. I want to use
it in darcs. But this will take some time.

BTW If there are any docs that should be updated I am ready to take over this.

Regards,
  Dmitry