This makes the regular expression a bit more complex, and potentially
slower, but it will fix the issue where users had noqa comments with
colons followed by explanations.

Closes #178

When attempting to centralize all inline NoQA handling in the StyleGuide
we inadvertently broke plugins relying on it in combination with checker
state. For example, the check for E402 relies both on NoQA and the state
to determine if it has seen a non-import line. Placing NoQA on the sole
line that is not an import is more elegant than placing it on each of
the following import lines.

Closes #186

McCabe reports C90* not C* and Flake8 2 used to exclude .eggs and *.egg

This is an emerging best practice and there is little reason to not
follow it