* Update basic.md to document JSON pointer for On Demand.
* Add automatic rewind for at_pointer
* Remove DOM examples in basics.md and update documentation reflecting addition of at_pointer automatic rewinding.
* Review
* Add test
* Naive implementation for doubles in string.
* Add double from string in atom doc.
* Simplification (removed all *_from_string())
* Add int and uint parsing in string.
* Make duplicates instead.
* Make tests exceptionless.
* Add missing declarations.
* Add more tests (errors, JSON pointer).
* Add crypto json tests.
* Update doc.
* Update doc after review.
Co-authored-by: Daniel Lemire <lemire@gmail.com>