Function call semantics

[danilopedraza]

I initially implemented this interpreter thinking in functions with several arguments/parameters. Now I don't like it. See the following example:

let f1(x, y) := x + y
let f2((x, y)) := x + y

Both of these do basically the same, but one accepts two parameters, and the other accepts a tuple with two elements. I think that I should restrict Komodo functions to accept only one parameters, and use tuples when we need more stuff, just like the functional programming gods intended.