Added module for handling AWS Virtual Private Clouds
This handles creating and editing VPCs and takes care of vpcs,
subnets, Internet Gateways, and route tables.
This adds a associate_public_ip parameter
The parameter defaults to true and sets things up so that VPC type instances
can get public IP addresses in non-default subnets.  The snag is that it
requires boto >= 2.13 which may be an issue for some deployments.