[nem-en] Marcos and intelligence

[Павел Блудов]

> The other solution would be enclose macro generated code in some kind
> of TExpr.MacroMarker(macro,expr). This would be removed by some later
> stage of the compiler (T2 or T3). I think this should be easy to
> implement.

It would be very nice.
And it would be very helpful to have the Location property in the IMacro 
interface like the IMember interface has.

-Paul.