Image: SensoMotoric Instruments  Apple’s attempts to hide the development of secret new products by using shell companies usually works, but some clever sleuthing by one site has revealed what may be a key component of Apple’s future with augmented reality. SEE ALSO: Cardboard augmented reality goggles? Please, no. We’ve done this dance before. Documents have been uncovered by MacRumors that indicate Apple has quietly acquired eye-tracking company SensoMotoric Instruments. In…