Add proper state output to ec2_asg, ec2_metric_alarm, ec2_scaling_policy

Fixes the exit_json calls for these modules so that they provide all the internal state.
This is required so that it's possible do access the arn information (amongst other things) which is required for things like hooking metric alarms and scaling policies together.

Example before/after for `ec2_metric_alarm` below. The other modules similarly go from printing almost nothing to printing everything I could get my hands on from boto.

```
ok: [localhost] => {
    "item": "",
    "metric_alarm_high": {
        "changed": false,
        "invocation": {
            "module_args": "",
            "module_name": "ec2_metric_alarm"
        },
        "item": ""
    }
}
```

```
ok: [localhost] => {
    "item": "",
    "metric_alarm_high": {
        "actions_enabled": "true",
        "alarm_actions": [
            "arn:aws:autoscaling:us-east-1:XXX:scalingPolicy:XXX:autoScalingGroupName/asg-XXX:policyName/asg-policy.XXX.high"
        ],
        "alarm_arn": "arn:aws:cloudwatch:us-east-1:XXX:alarm:XXX.cpu-high",
        "changed": false,
        "comparison": "GreaterThanOrEqualToThreshold",
        "description": "Reduce number of XXX when they're too busy",
        "dimensions": {
            "AutoScalingGroupName": [
                "asg-XXX"
            ]
        },
        "evaluation_periods": 3,
        "insufficient_data_actions": [],
        "invocation": {
            "module_args": "",
            "module_name": "ec2_metric_alarm"
        },
        "item": "",
        "last_updated": "2014-05-07T20:57:43.236Z",
        "metric": "CPUUtilization",
        "name": "XXX.cpu-high",
        "namespace": "AWS/EC2",
        "ok_actions": [],
        "period": 300,
        "state_reason": "Threshold Crossed: 2 datapoints were not greater than or equal to the threshold (50.0). The most recent datapoints: [0.352, 1.005].",
        "state_value": "OK",
        "statistic": "Average",
        "threshold": 50.0,
        "unit": "Percent"
    }
}
```