Make Style/EndOfLine configurable

[jonas054]

Based on discussions in #3401, I propose to add the following configuration option:

Style/EndOfLine:
  EnforcedStyle: lf
  SupportedStyles:
    - lf
    - crlf
    - native

The native option means crlf on Windows and lf on other platforms, and is the best choice for people running on Windows with core.autocrlf = true, if they are using git.

[poliva83]

@jonas054, will lf be the default configuration?

[jonas054]

I guess so. It's the rule in the style guide.

[poliva83]

I'd propose native makes more sense as the default as that was the behaviour <= 0.42.0. But I can probably get by with just setting it to native in some .rubocop.yml boilerplate used by all my git projects.

[abotalov]

I think native should be default because core.autocrlf = true is said to be a recommended setting for Windows in Github docs and Git Book

native setting is fully compatible with the Ruby Style guide rule:

If you're using Git you might want to add the following configuration setting to protect your project from Windows line endings creeping in:
$ git config --global core.autocrlf true

(core.autocrlf = true replaces LF with CRLF in all files on Windows)

[jonas054]

@poliva83 @abotalov I agree. Having native as default makes sense. My computer is being repaired. I'll take a look at this when I get it back, unless somebody else beats me to it.