Keep proper data type for JSON arrays between conversions.

[kra3]

If you convert a JSON array into XML and back to JSON, every data types in the array will be converted to string.

ie., {"k": [34, true, "val"]} -> xml -> json => {"k": ["34", "true", "val"]}

That's fixed in this commit as is done for JSONObjects.

[kra3]

If I'm correct, this pull request should also address #7

[kra3]

There is more to it in #7

@aalmiray I've created a pull request against the master branch (hence checks failing)
Do you want it to be submitted against develop?

[kra3]

Submitted a new pull request ( #33 ) on develop branch, so closing this.