Qkrisi

Found the issue. [DisplayManager](https://github.com/sinai-dev/UnityExplorer/blob/master/src/UI/DisplayManager.cs#L17) uses [Display.RelativeMouseAt](https://docs.unity3d.com/ScriptReference/Display.RelativeMouseAt.html), which as the Unity documentation states, isn't implemented for Linux, so it always returns `Vector3.zero`. I think it should just use the mouse position...