PK not respecting db column (via mailing list)
Places to test:
- setting up joins (follow_joins)
- select query count()
- parse select query special case for when just an id is selected .select("id") -> .select({Model: ['id']})
- convert_subquery
- annotate_query
- foreign related object lookup
- foreign key field
- model save
- model collect_queries
- delete instance

Model:

``` python
class Peer(BaseModel):
    peerId = PrimaryKeyField(db_column = 'id')
    macAddress = CharField()
    netAddress = CharField()
```

Error:

```
Traceback (most recent call last):
  File "/home/smoky/Documents/Workspace/TASv3/Code/tests/BusinessLogic/Results/Loggers/TestSQLLiteLogger.py", line 58, in testOldDataDestroyed
    assert len(Peer.select().count()) == 1
  File "/usr/local/lib/python2.7/dist-packages/peewee-0.9.1-py2.7.egg/peewee.py", line 1325, in count
    res = clone.database.execute(*clone.sql())
  File "/usr/local/lib/python2.7/dist-packages/peewee-0.9.1-py2.7.egg/peewee.py", line 310, in execute
    res = cursor.execute(sql, params or ())
OperationalError: no such column: peerId
```

It looks as if the db_column is being ignored by line 2371. Currently it is using attr.name, but surely it should use attr.db_column ?
