some hacking for ease of use and output

[varioustoxins]

I have adapted the code so

1. I have a function that builds spin system matrices from shifts, degeneracy and coupling
2. I have modified the output routines so you can plot to a file
3. I have added the ability to pass parameters to the plotting

Is it worth me converting these into pull requests

finally is it possible to isolate the lien components for each chemical shift so they can have different line widths (I could even imagine this being useful on a per multiple component level...

regards gary