Added docstrings to module functions and classes, explaining purpose and
function of the function/class. Outline the parameters and return types.
`is_path_spec` renamed to use snake_case. Constants also made globally
to the module.
This commit is a continuation from commit [3746b773f4] which is a
separation of library modules into its own package from a larger
project.
Version control jump is significant in feature implementations due
simply to under-using commit control after minor feature
implementations. Project will receive better commit messages going
forward on changes to the package.