fix focus problem

when user resize popup window, it get focus and WM_ACTIVE message be sent,
so I set foreground window active back.
when user move popup window, it won't get focus but when popup hide and
show again, it will be actived, showwindow(SW_NOACTIVE) do not work, and
no WM_ACTIVE message be sent,so I check if popup window is actived after
it shows