Gufo: A modern shell language!

I have corrected one major issue of Gufo this morning! On some terminals, without explanation, backspace was writting a h character instead of deleting a character. This is now undertood and solved: https://github.com/diml/lambda-term/issues/57 .

I have not a lot of time right now but with the correction of this bug, we get closer to a first Gufo release.