Unpacking syntax

[Richard (Rikki) Andrew Cattermole]

Looks quite nice.

A nice consequence of the type/storage class being required, is that 
we'd be able to support struct unpacking for fields as well with my 
proposed member-of-operator.

``(:field name) = s;``

I can probably assist in a first iteration of the DIP document after 
I've done member-of-operator which is up next. If that would be helpful.

Regardless, thanks for doing the thread write up, it seems fairly sane 
and expandable!