Consider adding support for Builder-style construction (via annotation-support)

[cowtowncoder]

One popular way of creating value type instances is that of using Builder-style construction; especially with frameworks such as Lombok and Immutables. It would be great if jackson-jr supported this too.

One practical thing that is unfortunate is that we cannot really use standard Jackson annotations (@JsonPOJOBuilder) since that is not part of jackson-annotations (but jackson-databind). So it would probably be necessary to add one or more annotations under jr-annotation-support.