[nem-en] Comments in standard library

[Vladimir Reshetnikov]

Why comments in standard library use semicolon as a list separator? E.g.

    /**
     * Returns reversed list, i.e. Rev([1;2;3]) = [3;2;1].
     * Works in time and memory O(n).
     */
    public Rev['a] (l : list ['a]) : list ['a] {