Aliased column is not converted to attribute when selected as alias as a part of join
Ah, `naive()` can help. Sorry.

``` python
class User(Model):
    ...

# it works in this way
for user in User.select(User, User.id.alias('some_alias_name'):
     print user.some_alias_name

# it does not in this way
for user in User.select(User, Group.id.alias('group_id')).join(Group):
     print user.group_id # AttributeError

# however
for user_dict in User.select(User, Group.id.alias('group_id')).join(Group).dicts():
     print 'group_id' in user_dict # True
```
