Node should only store mappings, sequences and scalars internally

[Herringway]

Eagerly converting values on load is lossy, which can be observed with exceptionally large integers and highly-precise decimals. It can also be rather expensive for the cases where a user isn't interested in every value in a document.

It SHOULD be an easy task to tackle, but it seems the support code runs real deep, and every attempt I've made so far has resulted in inexplicable test failures.