run all .py files through autopep8

i might like to at least crib parts of pyspectrograph, if not use it as a dependency, to refactor how the JWST ETC models the dispersed modes of NIRSpec and NIRISS. but first, i had to make the code style match. so i did:
```
find . -name "*.py" -exec autopep8 -a -i -v --max-line-length 120 {} \;
```
the changes are trivial, yet voluminous. use or discard as you wish...