Code had only a few reasons it wasn't compatible with Python3, and all
of them were bugs.

1) Inconsistent indentation. Sometimes tabs, sometimes spaces. That's a
recipe for trouble and that's why Python3 forbids it.

2) Ambiguity about whether the API values are bytestrings or unicode.
Being unsure is a sin, and Python 3 forces clear thinking here. No
behavior change for Py2, but Py 3 accepts using only unicode, and we
encode at the borders, when fabricating the JSON to send out.

3) print is a function in Python 3, not a statement, so those prints
have to look like function calls. That was surprisingly few changes,
and only one place had non-one arguments.

Remove hard tabs, trailing newlines, trailing spaces

Whitespace cleanups

Thanks Adam.