drop auto-loading and camelcase directories.

## Summary of changes

- drops unused items from `.gitignore`.
- drops camelCased directories and files in favor of lower "under_scored" names.
- moves utilities into `bin` directory and ensures they are `chmod +x`.
- drops superfluous namespaces in favor of simple `require` statement.
- drops code re-writing in tests in favor of simple copy and run workflow.
- uses most of PSR2 but ignores superfluous `MissingNamespace` and `SideEffects` rules.