I accidentally wrote sqlalchemy.sql.expressions instead of .functions at first, if that caused any confusion. Sorry.

In 0.9, `functions` doesn't export FunctionElement--it's private to the module. So functions.FunctionElement raises:

`AttributeError: 'module' object has no attribute 'FunctionElement'`

So I've imported FunctionElement individually. If you want to preserve `functions` as a namespace, we can change the import to:
```
try:
    from sqlalchemy.sql import functions
    functions.FunctionElement = __import__("sqlalchemy.sql.expression.FunctionElement")
except ImportError:  # SQLA < 0.9
    from sqlalchemy.sql import expression as functions
```

I think maybe that's clearer. Then the usage can remain functions.FunctionElement.