Fermi surface plotting

[harrisonlabollita]

This is a note for this feature to be added.

[harrisonlabollita]

Wien2k has a 2d Fermi surface plotting feature. The steps are the following:

1. generate the 2d mesh
2. run x spaghetti
3. run spagh2ho to convert to a file that can be used for contour plotting.
   This works well if one can successfully write the mesh. I have some hack scripts that get the job done, but plan on incorporating to the library as a shell script.