Simplifying linting experience

[brettcannon]

• flake8 or pylint? Evaluate pylint versus flake8 for common uses #553
• Provide a reasonable set of default linting rules Have a default set of linting rules #554
• 'Configure Linter' command 'Configure Linter' command #572

[brettcannon]

Since GitHub just launched some UX updates for projects, I have mirrored this meta issue to a project at https://github.com/Microsoft/vscode-python/projects/5 which I will manage.

[MikhailArkhipov]

df39217