Allow schema title to be used as class name (new useTitleAsClassname config option)

When having schemas where certain field names are repeated with different implementations the code currently generates unique class names such as Image__1, etc. I would like to have a configuration to use the title as class name instead.

So that

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "SchemaTest body",
  "description": "Use title as class name.",
  "type": "object",
  "properties": {
    "image": {
      "type": "object",
      "title": "MyImage"
    }
  }
}

would result in

public class SchemaTest {

    private MyImage image;

    public SchemaTest() {
    }

    public SchemaTest(MyImage image) {
        super();
        this.image = image;
    }

    public MyImage getImage() {
        return image;
    }
}

public class MyImage{
}

Thank you for your great library. I am using it successfully and really like the RuleFactory design.

[joelittlejohn]

Happy to accept a PR for this, as long as it is behind a configuration option, say, useTitleAsClassname. The default must be false.

[jrehwaldt]

Thank you very much! It was fun working on this one.