1. Update the field distortion models for FGS detectors (with new wcs definition). 2. Update README.md

2. Hotfix: fixed a bug when get the bandpasses for spectroscopic chips in Filter.py

2. swith to use "interFlux" in CatalogBase.py,
so now the implementation for number of photons been
shot in Photometric and Spectroscopic are the same
3. Minor config option fix in run_sim.py

fix the crashe when use a filter that is not in the list of run_chips for mag cut. add new feature: add additional output columns to the .cat file, see NGPCatalog.py as an example