[test] test case for fast open&close devtools from #1391
[README] update for 0.8.3
Merge pull request #1408 from kingFighter/test_#1391

[test] test case for fast open&close devtools from #1391
Add a 'quit' parameter to 'close' event cb

On OSX, when user hit 'Cmd-Q', the close event is
sent with a 'quit' parameter to distinguish with
other cases for closing window

Fix #430
bump version to 0.8.4