codespell (spell checker for source code)

codespell fixes common misspellings in text files. It's designed
primarily for checking misspelled words in source code, but it can be
used with other files as well.

Note: This is not the latest version of codespell. Version 2.2.2
can't be built on Slackware 15.0 due to needing too new of a
python-setuptools (I'm told it works on -current).
