Clean up manage.py

Removed a duplicate import and re-used the app instance for the script manager.
Merge pull request #3 from passy/patch-1

Clean up manage.py
Updated fbone/user/models.py for SQLAlchemy 0.8+

Mutabletype has been replaced by mutable in SQLAlchemy 0.8+
http://docs.sqlalchemy.org/en/latest/changelog/migration_08.html?highlight=mutabletype#mutabletype
This add compatibility with SQLAlchemy 0.8+
Merge pull request #6 from wassname/patch-1

Updated fbone/user/models.py for SQLAlchemy 0.8+