Change sliced FiberTrace Image/Profile/Mask to non-sliced MaskedImage

Currently the FiberTrace Image, Mask, and Profile are sliced so that the trace center is in the center pixel. Please change that into a rectangular CCD MaskedImage containing the profile and Mask pixels where the Mask pixels tell the user where the pixels belonging to an individual FiberTrace are located, plus a MaskedImage for the image of the observed spectrum. This way we can get rid of the FiberTraceFunction and all the functions that add a sliced FiberTrace representation back into a CCD image.