gitignore
Merge branch 'master' of https://github.com/alexfikl/school-work
Lots of work on cleaning up the scripts.

* added as many comments as i could for the moment
* added spaces and made everything more readable
* changed some notations (especially J -> N)
* using linspace more
* trying to use the imported scripts more
* made the imported scripts that contain the general data not solve any
problems. that doesn't make sense
* many small things here and there

There still SD and SP to comment and work out + some TODOs in dn and
Schx2D.