v1.0.0

This library was extracted from stlab/libraries (from stlab/adobe_source_libraries) and uses a new build, documentation, and test system.

A single feature has been added:
copy_on_write::write() now optionally takes a transform and an in-place transform function. If a copy is required, the transform function is invoked to make a copy and mutation in a single step; otherwise, the in-place transform is called to do the mutation.