Add isFocused method to nwWindow
Add isFocused method to nwWindow

chhe/livestreamer-twitch-gui,chhe/livestreamer-twitch-gui,streamlink/streamlink-twitch-gui,streamlink/streamlink-twitch-gui,bastimeyer/livestreamer-twitch-gui,bastimeyer/livestreamer-twitch-gui,chhe/livestreamer-twitch-gui,streamlink/streamlink-twitch-gui,bastimeyer/livestreamer-twitch-gui