Add proper error handling

[programaker]

In the current version, errors coming from type refinement or IO are not being properly handled. The idea is:

• Make all functions that can cause errors return Either[Error, A] (Refined already use Either, which makes things easier).

• Create an ErrorStep, to inform the error to the player and quit the game. The message to the player should be high level, but it can provide a way to generate a low level error report to "send to the developers"