Initial attempt at fromJson method in jackson module

[craigburke]

Let me know if I'm on the right track here. Once we get it to a point where it looks good I can add documentation as well.

[ldaley]

Thanks @craigburke!

This has highlighted a major problem with the Parser class. I'm going to pull this and then make the internal changes needed.

Can you add yourself as a contributor please: https://github.com/ratpack/ratpack/blob/master/ratpack-manual/src/content/chapters/99-about-the-project.md#contributors

I'll pull after that.

[ldaley]

I've got some time to work on this today, so I'm going to pull and we can address further work through another pull request.

[craigburke]

Sounds good! I'm anxious to see the Parser changes. I'll have some evening time in the next few days so let me know what else I could do for this.

[ldaley]

Changes went in here: f3edadb

Makes it possible to do parse(SomeType).

The documentation in the area of parsing and the Jackson stuff in general is pretty weak. Any help there at all would be very welcome :)

Don't forget to send a PR with yourself added to the contributors list at least.

[craigburke]

Yeah, I saw that change, that's awesome! I can definitely take a stab at adding some documentation there. It's a good excuse to dig into that code a bit more.