Query iteration bug?
Check out:
- https://github.com/coleifer/peewee/issues/12#issuecomment-5614404
- https://github.com/coleifer/peewee/issues/81

``` python
from peewee import *
from datetime import datetime

db = SqliteDatabase('test.db')

class A(Model):
    id = PrimaryKeyField()
    date = DateTimeField()
    class Meta:
        database = db

A.create_table(fail_silently = True);
if not A.select().count():
    A(date = datetime.now()).save()
    A(date = datetime.now()).save()

print('%d records' % A.select().count())
count = 0;
for a in A.select():
    count += 1
    print('%d: %d' % (count, a.id))
    a.save()
```

Output:

```
>python test.py
2 records
1: 1
2: 2
3: 1
4: 2
```

Python 2.7.8 (default, Jun 30 2014, 16:03:49) [MSC v.1500 32 bit (Intel)] on win32

If I comment the line "a.save()", it iterates only twice, as I would expect. Am I doing something wrong?
