namedtuple derivatives

namedtuple

namedtuple is implemented an eval'd string in python, this implementation would likely copy that

```python
import geohash

Foo = initializednamedtuple('Foo', [
   'lat',
   'long',
   ('geohash', lambda self, geohash: geohash if geohash else geohash.geohash(self.lat, self.long))
])
```

I'm not even sure if closure conversion would work right

List arguments are optionally tuples, if a tuple is present the second value is a function, if present as a pair the first function argument is 'self', otherwise the argument is the argument passed

```python
Foo = typednametuple('Bar', [
    Integer('lat'),
    Integer('long'),
    Optional(Float('geohash', lambda self: geohash.geohash(self.lat, self.long)))
]
```

For Optionals, the second argument is the initialization function if it isn't passed and takes self.

Integer -> int
Float -> float
String -> str

pystachio like stuff