PSR-4

[Luc45]

Is your enhancement related to a problem? Please describe.
It's hard to adhere to the Single Responsibility Principle without an auto-loader.

Describe the solution you'd like
The most popular auto-loader in PHP today is the PSR-4 standard provided by Composer. The code will need a little bit of refactoring to accomplish this, but the good side is that the codebase is small and the lift is not huge.

PS: I'm sorry if I'm meddling my nose in an undesirable way in the code. I thought feedback could be wanted, given the open-source nature of the project.