* [ec2_ami_facts] new boto3-based module as a replacement for ec2_ami_find
- new boto3-based module to gather facts about ec2 images
- intended to replace ec2_ami_find which uses boto
- an ami find task (using new module) added to the ec2_ami integration test
* [ec2_ami_facts] Use AnsibleAWSModule. Catch BotoCoreError.
* add ec2_ami_facts alias to tests
* [ec2_ami_facts] return ami launch permissions as well
