Allow newline between arguments to a call-expression

[stasm]

After #2 is fixed, we'll run into a similar problem as the one described in l20n/spec#14, but for arglist: the current grammar doesn't allow new lines in the list of arguments to a call-expression. It makes the complex examples from the syntax guide invalid:

liked-photo = { LEN($people) ->
    [1] { $people } likes
    [2] { $people } like
    [3] { LIST(TAKE(2, $people), "one more person") } like

   *[other] { LIST(
        TAKE(2, $people),
        "{ LEN(DROP(2, $people)) ->
            [1]    one more person like
           *[other]  { LEN(DROP(2, $people)) } more people like
        }"
    ) }
} your photo.

[stasm]

@zbraniecki In order to ensure good error recovery, does this has a dependency on #12?

I'm going to move this to the 0.3 milestone which is mostly about making our white-space story well-defined.

[zbraniecki]

no, it doesn't depend on #12.

[stasm]

This was fixed by #32.