merge add_target into `h2o_socketpool_connect` now that the logic is specific to the global pool
merge add_target into `h2o_socketpool_connect` now that the logic is specific to the global pool

zlm2012/h2o,deweerdt/h2o,deweerdt/h2o,lkwg82/h2o,lkwg82/h2o,zlm2012/h2o,h2o/h2o,zlm2012/h2o,h2o/h2o,lkwg82/h2o,deweerdt/h2o,deweerdt/h2o,devnexen/h2o,devnexen/h2o,h2o/h2o,zlm2012/h2o,lkwg82/h2o,yannick/h2o,cwyang/h2o,h2o/h2o,zlm2012/h2o,cwyang/h2o,lkwg82/h2o,cwyang/h2o,devnexen/h2o,deweerdt/h2o,yannick/h2o,lkwg82/h2o,cwyang/h2o,yannick/h2o,zlm2012/h2o,deweerdt/h2o,h2o/h2o,cwyang/h2o,lkwg82/h2o,lkwg82/h2o,h2o/h2o,yannick/h2o,devnexen/h2o,zlm2012/h2o,h2o/h2o,yannick/h2o,cwyang/h2o,devnexen/h2o,devnexen/h2o,deweerdt/h2o,h2o/h2o,cwyang/h2o,yannick/h2o,deweerdt/h2o,deweerdt/h2o,devnexen/h2o,yannick/h2o,devnexen/h2o,cwyang/h2o,h2o/h2o,yannick/h2o,zlm2012/h2o,lkwg82/h2o,zlm2012/h2o,devnexen/h2o,yannick/h2o