Pyflakes

- Fix reported line number for type comment errors
- Fix typing.overload check to only check imported names

- Allow intentional assignment to variables named ``_``
- Recognize ``__module__`` as a valid name in class scope
- ``pyflakes.checker.Checker`` supports checking of partial ``ast`` trees
- Detect assign-before-use for local variables which shadow builtin names
- Detect invalid ``print`` syntax using ``>>`` operator
- Treat ``async for`` the same as a ``for`` loop for introducing variables
- Add detection for list concatenation in ``__all__``
- Exempt ``typing.overload`` from duplicate function declaration
- Importing a submodule of an ``as``-aliased ``import``-import is marked as
used
- Report undefined names from ``__all__`` as possibly coming from a ``*``
import
- Add support for changes in Python 3.8-dev
- Add support for PEP 563 (``from __future__ import annotations``)
- Include Python version and platform information in ``pyflakes --version``
- Recognize ``__annotations__`` as a valid magic global in Python 3.6+
- Mark names used in PEP 484 `` type: ...`` comments as used
- Add check for use of ``is`` operator with ``str``, ``bytes``, and ``int``
literals

- Drop support for EOL Python <2.7 and 3.2-3.3
- Check for unused exception binding in ``except:`` block
- Handle string literal type annotations
- Ignore redefinitions of ``_``, unless originally defined by import
- Support ``__class__`` without ``self`` in Python 3
- Issue an error for ``raise NotImplemented(...)``

- Process function scope variable annotations for used names
- Find Python files without extensions by their shebang

- Enable support for PEP 526 annotated assignments

- Change formatting of ImportStarMessage to be consistent with other errors
- Support PEP 498 "f-strings"