feat(Examples): add play area boundary pointer cursor
feat(Examples): add play area boundary pointer cursor

The teleporter example scene has been updated so the bezier pointer
cursors also include a representation of the play area boundaries
and show it in an offset relation to where the player is standing
within their play area boundaries.

thestonefox/SteamVR_Unity_Toolkit,thestonefox/VRTK,gomez-addams/SteamVR_Unity_Toolkit