Lambda application prototype done, module doesn't compile yet though
Deleted unused test file without content
Lambda application finished (not tested). Lambda creation out of atom still missing, see ### TODO ### CONTINUE in Evaluate.hs.
Almost works. To do: debug 'begin'.
Fixed begin

Fold functions like this wouldn't work:
> begin envR (x:xs) = fold[r]M f x xs
>       where f x _ = evaluate envR x
They either returned wrong results or evaluated the wrong way round.
Maybe that's something to refactor later on.
Fixed if not evaluating the predicate

The predicate wasn't evaluated, so if it wasn't an explicit Bool, it was
treated as True. For example
> (if (> 3 2) 'yes 'no)
would return 'no', as (> 3 2) is not #t, although it of course evaluates
to #t.
Small comment updates in Evaluate.hs
Merge branch 'lambdas'
Made begin more explicit
Implemented 'let' bindings