toFront flashes task bar icon in JUCEApplication::anotherInstanceStarted

If false is returned from JUCEApplication::moreThanOneInstanceAllowed and you attempt to bring your main window to the foreground by calling toFront in response to JUCEApplication::anotherInstanceStarted, the window’s task bar icon simply flashes.

In Windows, this is by design. However, calling AllowSetForegroundWindow in JUCEApplicationBase::MultipleInstanceHandler::sendCommandLineToPreexistingInstance allows the existing instance’s call of toFront to succeed.