Update communicator.go

If block ends in a return statement.  Personal preference. It's less explicit, but more concise to drop the else and outdent the return.
Add 'security_groups' and 'subnets' args to 'aws_elb'
Implement specification of AWS security groups in ingress rules as <owner>/<id>
add vpc dns attribute support
website: another attempt
website: make it clearer how to retrieve DO key info
config: validate no interp in var [GH-180]
config: HCL loader
terraform: register a type
providers/aws: fix RDB test syntax error
Fixes #179 -- expand ~'s in the path to a key file
Added a test and fixed a typo
website: fix downloads
Added a second test for the other form of tilde paths
config: use new HCL lib and structure
config: only walk if non-nil
Document that variable files can also be JSON, and clarify that terraform.tfvars is searched for in the *current* directory
terraform: fix potential case where cycle is made
helper/schema: initial work
Ports Packer code to load CLI configuration and external plugins