Add trailing comma in formatted stringify

[jordanbtucker]

Since one of the goals of JSON5 is to be more easily writable for humans, and since I happened to find this project by Googling "json trailing comma", I think it makes sense for JSON5 to output text that is more easily writable for humans too.

The examples in the README would be output as (note the added trailing commas):

{
    foo: "bar",
    while: true,
    this: "is a multi-line string",
    here: "is another",
    hex: 3735928559,
    half: 0.5,
    delta: 10,
    to: null,
    finally: "a trailing comma",
    oh: [
        "we shouldn't forget",
        "arrays can have",
        "trailing commas too",
    ],
}

{
    name: "json5",
    version: "0.2.0",
    description: "JSON for the ES5 era.",
    keywords: [
        "json",
        "es5",
    ],
    author: "Aseem Kishore <aseem.kishore@gmail.com>",
    contributors: [
        "Max Nanasy <max.nanasy@gmail.com>",
    ],
    main: "lib/json5.js",
    bin: "lib/cli.js",
    dependencies: {},
    devDependencies: {
        mocha: "~1.0.3",
    },
    scripts: {
        build: "./lib/cli.js -c package.json5",
        test: "mocha --ui exports --reporter spec",
    },
    homepage: "http://json5.org/",
    repository: {
        type: "git",
        url: "https://github.com/aseemk/json5.git",
    },
}

Of course, this would only be when the space argument is specified with a truthy value. Otherwise, JSON5 should probably output text as compact as possible.

Thoughts?

[jordanbtucker]

I also just noticed that JSON5 is outputting Infinity as null.

[aseemk]

👍 to the idea from me. =)

[jordanbtucker]

Fixed in 35269da