GUI-337: Only display EC2-specific condition keys for their respective actions per AWS docs.

Relevant AWS docs are at http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-policies-for-amazon-ec2.html#ec2-supported-iam-actions-resources
GUI-337: Map tenancy condition key to string value
Merge pull request #279 from eucalyptus/GUI-337

GUI-337: IAM Policy Generator - Selective display of condition keys based on actions