Support more syntaxes in per-file-ignores

Closes #471

See merge request pycqa/flake8!281

Remove unused PROJECT_FILENAMES

See merge request pycqa/flake8!279

Enforce warnings under test

Closes #275

See merge request pycqa/flake8!280

Remove tests_require / setup_requires since we do not use setup.py test

See merge request pycqa/flake8!277

Call pyflakes api better

See merge request pycqa/flake8!276

Remove unused and broken flake8.listen plugin type

Closes #480

See merge request pycqa/flake8!274

Accept Noqa without space

Closes #470

See merge request pycqa/flake8!273

This provides a step by step doc for the regular expression, and makes iterating on it much easier

Recommend registering plugin options using `add_options` and `parse_options`...

See merge request pycqa/flake8!272

Recommend registering plugin options using `add_options` and `parse_options` rather then `register_options` and `provide_options` since these are actually called.

Allow physical checks to return multiple results

See merge request pycqa/flake8!269

Remove workarounds for older, unsupported Pythons

See merge request pycqa/flake8!271

Remove unused verify_requirements argument

See merge request pycqa/flake8!267

Add https://pre-commit.com metadata

See merge request pycqa/flake8!268

Replace setuptools with entrypoints

See merge request pycqa/flake8!264

Grammar fixes

See merge request pycqa/flake8!266

Add support for per-file ignores in config

Closes #156

See merge request pycqa/flake8!259

Clearer docs, NOQA_INLINE_REGEXP comment - fixes #469

Closes #469

See merge request pycqa/flake8!262

Add documentation for `flake8 --extend-ignore`

See merge request pycqa/flake8!258

Most of the problems with our logic were due to not having the same
logic as our exclude parameter. This refactors that out into a separate
function so we can confidently achieve that.

These show that there were some subtle bugs in how we were matching
things and that there are bugs that need to be fixed.