Add scene from subpixel display capability

1. Edit sceneFromFile
2. in vcReadImage, check if we need to convert to sub pixel image
Add displayCompute routine

This function can help calculate the sub pixel image from an rob image
First update GUI for display

Convert GUI from ctToolbox to ISETBIO, more work to be done.
In the future, I hope we could use display as something similar to
scene. Such as vcAddAndSelectObject(‘display’, d) and displayWindow