Not working anymore with the new steamVR update

[EdgarPironti]

The action mechanism makes the ViveUILaserPointer.cs script deprecated.
I solved using the SteamVR_Action_Boolean and removing the device.GetPressDown and all device related lines.

Not sure if and how to include the new Action mapping in the repository, before proposing a PR.

[paulhayes]

Would be interesting to see this in action.