change the semantics of the write callback for polling transports. fire upon flush, not drain
change the semantics of the write callback for polling transports. fire upon flush, not drain

julianduque/engine.io-client,AnyPresence/engine.io-client,lwahonen/engine.io-client,juancancela/engine.io-client,nkzawa/engine.io-client,socketio/engine.io-client,sanemat/engine.io-client,vedmalex/engine.io-client,juancarloscancela/engine.io-client,Automattic/engine.io-client,socketio/engine.io-client,enounca/engine.io-client,socketio/engine.io-client,hellpf/engine.io-client,SpainTrain/engine.io-client,gsklee/engine.io-client,jskrzypek/engine.io-client,BernhardRode/engine.io-client