Add support for data lookup based on index values

[wcmjunior]

The user must be able to get specific data based on its original index position on the original data used as input bind. For images, as an example, must exists a method like "getPixel" in which the user gets the pixel data base on its original (x,y) coordinates. For arrays it must also be supported. It is mandatory that these methods can be called from an user kernel.