Fix #116: add read/write support for java.nio.file.Path

[cowtowncoder]

No description provided.

[jhonnen]

Should a Path really be serialised as an URI? I would have assumed you could interchange Path and File while reading and writing the same JSON string.

[cowtowncoder]

@jhonnen I was looking at what Jackson databind does and followed that. But I am open to counter arguments -- and PRs would be welcome for changed behavior (and tests).
We can easily change it now before this gets released in 2.17.

[jhonnen]

Following Jackson databind is a good point. I just think it's confusing that

{ "x": "/some/path" }

can only be deserialized as File but not as Path.

[cowtowncoder]

@jhonnen As I said, I am totally open to alternative handling, since I do not actually have use for this myself.
So if you feel different handling makes sense, I would really appreciate a PR for improvement (just so I do not misunderstand some point; unit test showing exactly expected behavior).

And in fact use of Path.toString() would sort of go with least-surprise approach (even if less stable for round-tripping).