The python source code usually uses "customiz*" (341 instances) over "customis*" (19 instance, 8 of which are in logging).

I realize "foolish consistency", and all that, but I think the documentation should all use the same conventions. I'd be happy to change the documentation.

Most of these changes are in documentation or docstrings, but some are in comments. Which is why I'm assigning to docs@. I didn't change 2.0.rst, because that seemed like a historical document.