Moved _is_button_enabled() to util section
Moved _is_button_enabled() to util section

Distrotech/libbluray,zxlooong/libbluray,Azzuro/libbluray,ace20022/libbluray,Distrotech/libbluray,mwgoldsmith/bluray,ShiftMediaProject/libbluray,Azzuro/libbluray,tourettes/libbluray,ace20022/libbluray,UIKit0/libbluray,tourettes/libbluray,vlc-mirror/libbluray,ShiftMediaProject/libbluray,zxlooong/libbluray,pingflood/libbluray,mwgoldsmith/bluray,EdwardNewK/libbluray,EdwardNewK/libbluray,Distrotech/libbluray,pingflood/libbluray,UIKit0/libbluray,UIKit0/libbluray,Distrotech/libbluray,ace20022/libbluray,UIKit0/libbluray,tourettes/libbluray,koying/libbluray,ShiftMediaProject/libbluray,koying/libbluray,koying/libbluray,vlc-mirror/libbluray,vlc-mirror/libbluray,mwgoldsmith/bluray,ShiftMediaProject/libbluray,zxlooong/libbluray,Azzuro/libbluray,koying/libbluray,ace20022/libbluray,pingflood/libbluray,tourettes/libbluray,vlc-mirror/libbluray,EdwardNewK/libbluray,EdwardNewK/libbluray,Azzuro/libbluray,mwgoldsmith/bluray