Added missing map type at ScelenLoader.js

Adds method to zero VR sensors

navigator.mozGetVRDevices check is not necessary anymore since Firefox d...

Handling case when the orientation of VR state is null. For some devices...

Handling case when the orientation of VR state is null. For some devices the information might not be available and the API will return null

Use . instead of / for members in docs URLs

Improved cross-referencing in documentation