Allow collapsing json output and fix bug with quotes within a value

[ahsquared]

Hi Martin,

Awesome tool! Love it! Had a bug though when I had quotes within a value, e.g. in the following csv data:
foo bar "baz" more foo

the json output would be:
[
{
"foo": "bar "baz" // missing quote here
},
{
"foo": "more foo"
}
]

I removed the trim('"') on the value and tested with lots of inputs and it seems to work. You may have had a good reason for this - would like to know - but for my use cases this works.

I also needed collapsed output, so added an option for that, that just uses JSON.stringify(json).

Cheers,
Andre