A simpler kafka consumer

```
kafka = KafkaConsumer('topic1')
for m in kafka:
    print m

kafka = KafkaConsumer('topic1', 'topic2',
                      group_id='my_consumer_group',
                      auto_commit_enable=True,
                      auto_commit_interval_ms=30 * 1000,
                      auto_offset_reset='smallest')

for m in kafka:
    process_message(m)
    kafka.task_done(m)
```
disagree.  **kwargs seems to be the generally accepted pythonic interface.  Plus if you wanted to load a dictionary of configs from a file or elsewhere, you could convert it to kwargs easily:

```
config = dict()
config.update(load_parameters_from_file())
kafka = KafkaConsumer('topic1', 'topic2', **config)
```

Unless there is something special about java properties (not really a dict?), I don't see the need to worry about this.