[golo-dev] new feature: list comprehension

[Yannick Loiseau <me@xxxxxxxxxxxx>]

Hi  everyone,

my last PR adds list comprehension to Golo, e.g.

  let mySet = set[ "foo: " + (x / 2) + ";" + y 
                    foreach x in [1..10] when (x % 2) == 0
                    foreach y in ["a", "b", "c"] ]

Any comments on the code, doc, or feature itself?

- Yannick