Crash if user double clicks to close

[plaetzchen]

Hi there,

The component crashes if the user (for what ever reason) double clicks the NSStatusItem to close the popover. This is a fixed hidePopover method:

- (void)hidePopover
{
    if (_popover && _popover.isShown && self.active) {
        [_popover close];
        [NSEvent removeMonitor:_popoverTransiencyMonitor];
    }

    self.active = NO;

}

[dennispassway]

:+1: This should be fixed.