A suggestion on keyword for_each

[Dicebot]

`foreach_reverse` is a major design mistake considering the fact 
that it requires a very specific range type, contrary to normal 
range. For lot of ranges concept of iteration order is simply not 
defined making `foreach_reverse` useless. And in rare cases when 
it is needed, it can be replaced with plain `for`.

Hardly does any harm, but definitely not worth putting any 
efforts into it.