Warning deprecation

1st commit: Changing code, to follow up with pyramid changes (and deprecation). I remember reading somewhere, that deprecation warning live for three major releases. Also: Shouldn't we force update to at least pyramid 1.1. in setup.py?

2nd: squelching SAWarning: Unicode type received non-unicode bind param value. Either like that, or login field should be defined like that:

```python

class User(Base):

    # ...

    login = Column(String(255, convert_unicode=True), nullable=False)

    # ...


```