Roadmap

Roughly in order of priority:

Improve float parsing to not use sscanf(), which can cause quadratic complexity with non-terminated strings.
Conformance of the parser to the YAML standard:
- Increase success rate of YAML test suite parsing (as of May 2020, ~30/1300 tests are failing)
- Cross-check the suite test correctness with the events specified in each test. (Currently the tests are only checking for successful parsing and idempotent emitting).
- Run the suite tests also on the Windows CI (Appveyor).
Cleanup:
- Review & cleanup API surface.
- turn calls to C4_ASSERT() into calls to RYML_ASSERT()
- use c4::MemoryResource in place of c4::yml::MemoryResource, and remove c4::yml::MemoryResource
- same for allocators and error callbacks: Use the facilities from c4core.
Review parse() API: add suffixes _in_situ and _in_arena to clarify intent. Ie:
- rename parse(substr) to parse_in_situ(substr)
- rename parse(csubstr) to parse_in_arena(csubstr)
Add emit formatting controls:
- add single-line flow formatter
- add multi-line flow formatters
  - indenting
  - non indenting
- keep current block formatter
- add customizable linebreak limits (number of columns) to every formatter
- add per node format flags
- (lesser priority) add auto formatter using reasonable heuristics to switch between other existing formatters
use csubstr instead of csubstr const& in return and parameter types, but quantify the performance effect.
Investigate possibility of comment-preserving roundtrips