* provider/aws: New DataSource: aws_elb_hosted_zone_id
This datasource is a list of all of the ELB DualStack Hosted Zone IDs.
This will allow us to reference the correct hosted zone id when creating
route53 alias records
There are many bugs for this - this is just the beginning of fixing them
```
% make testacc TEST=./builtin/providers/aws TESTARGS='-run=TestAccAWSElbHostedZoneId_basic'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2017/01/04 13:04:32 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/aws -v -run=TestAccAWSElbHostedZoneId_basic -timeout 120m
=== RUN TestAccAWSElbHostedZoneId_basic
--- PASS: TestAccAWSElbHostedZoneId_basic (20.46s)
PASS
ok github.com/hashicorp/terraform/builtin/providers/aws 20.484s
```
* Update elb_hosted_zone_id.html.markdown
Paul Stack