On macOS, now closing the window will actually hide the window
instead of quit the application, thus it will match to some other
macOS application's behavior.
Additionally, since our binary is not signed, this could avoid
seeing the request permission dialogs everytime user attempts to
open an image file inside a private place (e.g. places like the
"Downloads" folder and "access data from other apps").
Gary Wang
6d7d0e4e1d