Update events_windows.go

WM_CLOSE is a close request (ie the X has been clicked). Code for unregistering MsgHandler and posting destroy message is moved to the Close() method.
Update win_windows.go

Close should not generate a "request to close" msg (WM_CLOSE) but an actual close msg (WM_DESTROY)

Close events can be handled.
Update win_windows.go

missing "this"
Update AUTHORS
Merge pull request #28 from ctlod/patch-1

Windows Close Events