Increase timeout for IAM role creation
Add support for conditions in IAM policies
Move user-data handling into its own plugin

This leaves as the sole concern for instance launch maintaining the
interface to the underlying AWS APIs.

The handling that was being performed is very much tied to Ubuntu's
CloudInit project and should be maintained separately. This should also
make it easier to add the missing gzipping of multipart mime-encoded
user-data sections, which will be needed sooner or later.
Ignore null/empty entries
Explicitly add user_data plugin to list of default

The plugin would be picked up implicitly, even by default. Still, there
is no harm done in having it listed explicitly, which is more
future-proof.
Fix validation of instance attribute 'shutdown-behavior'

Accepts string values 'stop' and 'terminate'.
Setup logging, so modules can use it

Introduces a --verbose command line option, to expose the verbosity
level to the user. Mostly useful for debugging.
AMI Image Search plugin

This exposes EC2's DescribeImages API call. All filters currently
available in the API are exposed, but not validated. This construct does
not accept queries by ImageId, as that would be rather pointless here.

Wildcard characters '*' and '?' are recognized in filter values. Online
AWS docs have more info:

    http://docs.aws.amazon.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeImages.html

This allows instance definitions to be (a bit)gq more independent of
specific regions and enables them to effectively track the latest
version of a specific distribution.`