json.tolerantParse(...) API should be tolerant of trailing commas with trailing comments

[DustinCampbell]

The following unit test should pass:

test("ignore trailing comma in object member list with comment at end of line", () => {
    const text =
        `{
"obj": {
    "a" : 1, // Comment
}
}`;

    const expected =
        `{
"obj": {
    "a": 1
}
}`;

    let json = tolerantParse(text);
    let result = JSON.stringify(json, null, 4);

    result.should.equal(expected);
});

[rchande]

@DustinCampbell Given that we deprecated project.json support, do we still need to do this?

[DustinCampbell]

Yeah, I don't think we need this anymore. FWIW, #1237 would be a better investment anyway.