Optimize creation of the request bucket.
Optimize creation of the request bucket.

* buckets/request_buckets.c
  (serialize_data): Avoid copying the request line components to a new string
      by using an iovec_bucket.

justinweb/serf,sworda/serf,blueszhangsh/serf,Manouchehri/serf,sworda/serf,krime/serf,TommyU/serf,sworda/serf,blueszhangsh/serf,krime/serf,justinweb/serf,Manouchehri/serf,TommyU/serf,justinweb/serf,wzugang/serf,krime/serf,muthusuba/serf,idomon/serf,blueszhangsh/serf,liuzongquan/serf,idomon/serf,Manouchehri/serf,liuzongquan/serf,liuzongquan/serf,justinweb/serf,muthusuba/serf,TommyU/serf,wzugang/serf,sworda/serf,idomon/serf,liuzongquan/serf,blueszhangsh/serf,TommyU/serf,idomon/serf,krime/serf,muthusuba/serf,wzugang/serf,wzugang/serf,muthusuba/serf,Manouchehri/serf