Initial macro approach

We need a simple macro evaluation engine.

E.g. having a program like
```
(defmacro defmain (body)
  (list .method "Main" int (list)
    body)
)
(.assembly "dfdf"
  (defmain (.call Console.WriteLine "ozozoz"))
)
```

Naggum should be able to construct the assembly with a main method calling `Console.WriteLine`.

(The syntax is still preliminal.)