Upgrade NW.js to 0.37.4
Upgrade NW.js to 0.37.4

Resolves #629

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