Properly deal with bright defocused objects

[cwwalter]

In testing imSim 2.0 I saw we neglected to handle the case where very bright objects are being imaged on out-of-focus sensors. This includes both the wavefront sensors and intra and extra focal focal plane images. This is due to the switch over to FFT imaging for very bright objects which bypasses the ray-tracing.

The following image demonstrates the problem. Note the in-focus bright stars among the donuts: