mod utils.py:get_instance_metadata allowing access to dynamic data

dynamic metadata gives some more info about an instance and is exposed through the metadata api, namely different are:
accountId
architecture
availabilityZone
billingProducts
devpayProductCodes
imageId
instanceId
instanceType
kernelId
pendingTime
pkcs7
privateIp
ramdiskId
region
signature
version

I kept the default behavior of grabbing "meta-data", but removed it from being hard-coded so you can access the above by passing data="dynamic".