allow overriding the EOL string

[kellyselden]

Closes #87.

I decided to make it an optional setting as to not cause any grief to anyone. We can always change the default to from '\n' to require('os').EOL in the future if we want to do a major version bump if we consider it a breaking change.

[jprichardson]

I just thought of something... does the JSON standard specify an EOL? Or does it state it should be platform specific?

[kellyselden]

I'm not sure, but I think once you start involving the file-system, it is your court to format it as you please? Maybe I'm wrong.

I doubt there's a bug in JSON.stringify, so they are probably correctly forcing '\n'. I don't necessarily like that, but it is probably correct to spec.

[RyanZim]

The json spec doesn't define any newlines; matter of fact, it doesn't define any formatting; JSON formatting is simply a convention. Here's all the spec has to say:

   Insignificant whitespace is allowed before or after any of the six
   structural characters.

      ws = *(
                %x20 /              ; Space
                %x09 /              ; Horizontal tab
                %x0A /              ; Line feed or New line
                %x0D                ; Carriage return
            )

The EcmaScript spec defines that it shall be a linefeed. I think we should keep this the default; users can override if they wish.

[RyanZim]

One thing I wonder about; is it wise to have this as a global setting on jsonfile.EOL? I know we do this for spaces, but I consider it a bad practice since settings are global to all modules in the Node process.

[kellyselden]

I could go either way.

[kellyselden]

Is this OK to merge, or should I change the global option?

[RyanZim]

Let's remove the global.

[kellyselden]

Global removed

[jprichardson]

Thanks @kellyselden!