[Patch 1.1] Update with 'Look Selection' and Xbox and Keyboard input

Features

• Look selection which now allows users without Vive controllers to interact with UI by looking at them
• The Xbox controller's A button can now be used to 'click' on highlighted ui
• The keyboard can now be used to 'click' by pressing the Space or Enter keys
• Added support for returning to the menu using the Xbox controller's Start button
• Added support for returning to the menu using the Escape key on the keyboard
• Added warning message when SteamVR is not detected

The next update will bring major performance improvements to reduce stuttering and latency.

BuildID: 1104106