Implement serf_bucket_get_remaining() for LIMIT buckets.
Implement serf_bucket_get_remaining() for LIMIT buckets.

* buckets/limit_buckets.c
  (serf_limit_get_remaining): New.
  (serf_bucket_type_limit): Add serf_limit_get_remaining().

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