Refactoring to support container-interop

- Now supports [container-interop](https://github.com/container-interop/container-interop)
- Extract alias handling logic from `XStatic` into `AliasLoader`
- Removed `Jeremeamia` from the namespace
- Changed up the API significantly
- Made the alias root namespace configurable
- PSR-4 compatible

This PR is WIP while I wrap up testing. Feedback is welcome.