Suggest adding some apis to get status of the controls

[lynnic26]

Hi,
now we inspect DOM to see the status of controls, it is not so convenient
can your guys add some apis to get status of controls ?
for example:
get the status of fullscreen and whether the bullet is enabled and so on via player instance directly

希望能添加一些可以获取控件状态的api, 比如弹幕是否开启、全屏是否开启
现在的方式是用js查看DOM的状态，有点不方便

Thanks : ）

[zhangxin92]

Fixed by bb8079 with adding fullsceen, bullet, textTrack, picture-in-picture status. Can be used in v1.0.9.