Spectral extraction

[astrochun]

GNIRS's nsextract is not an ideal extraction code. It cannot handle individual emission lines so well. I decided to create a separate module to extract (Extract1D) and a code to compute the distortion-based extraction solution from bright continuum source. The latter is called distort_trace.py.

[astrochun]

After modifications to distort_trace.py and Extract1D, I'm now calling them in reduce.run(). Here, I'm prompting users for the coordinates (they will need to examine the combined image), and passing that to Extract1D.extract [bd86786, a43d06f]