js: allow keycode to be the member of KeyManager
js: allow keycode to be the member of KeyManager

guicho271828/2017-6-14-aist-interview,guicho271828/2017-6-14-aist-interview,guicho271828/2017-6-14-aist-interview,guicho271828/2017-6-14-aist-interview,guicho271828/2017-6-14-aist-interview