add `versionadded` note for `retry_max_delay`
add `versionadded` note for `retry_max_delay`

rockerbox/kazoo,max0d41/kazoo,jacksontj/kazoo,pombredanne/kazoo,rgs1/kazoo,bsanders/kazoo,rackerlabs/kazoo,pombredanne/kazoo,rackerlabs/kazoo,rockerbox/kazoo,AlexanderplUs/kazoo,python-zk/kazoo,tempbottle/kazoo,bsanders/kazoo,jacksontj/kazoo,harlowja/kazoo,rgs1/kazoo,kormat/kazoo,max0d41/kazoo,kormat/kazoo,tempbottle/kazoo,python-zk/kazoo,harlowja/kazoo,Asana/kazoo,AlexanderplUs/kazoo