Directory reorganization

I reorganized folders to keep the top-level directory from getting out of control.  Routines are now organized by function (processing data, imaging, spectra, etc).  There's a chance some code might break, but this should be easy to fix.  You also need all the subdirectory paths are added in your IDL session -- the routines generally assume you are working from the "foxsi-science" main directory.

I also added folders for individual people, so routines or snippets that Sa"m and Ishikawa have given me are now in folders with their names on it.  (Steven, feel free to make one for you if you want.)  In some cases, I've taken some of this code, edited it slightly, and added it to the applicable subdirectory.  So, for example, some of the "img" routines were written by Ishikawa and edited by me, but if you want to see the original routines and scripts that he wrote then look in the directory with his name on it.  Similarly, if you're curious about the blanket calibration I'm doing, you can comb through the miles of code in my folder.

The "plots" folder is not complete but has some of the plots we've generated so far.

I updated the README.md file to include an index of all the folders.