10. full text search. (class decorator for model?)

12. fomal docs, including a comprehensive example

19. _avatar = Column('avatar', LargeBinary)
    def get_avatar(self):
        if not self._avatar:
            return default_avatar
    def set_avatar(self, data):
        self._avatar = data
    avatar = property(get_avatar, set_avatar)

    equivalent to  "avatar = Column(LargeBinary, default = default_avatar)"
    but the default value isn't saved to database, preferred.
    there should be a convenient way to do this. (preferrablly by one line of code)

25. move content in __init__() to DatabaseExtension?

26. orm for nosql? such as this one: http://qslack.com/projects/rhino-a-ruby-hbase-orm/
