It was not possible to delete AWS DNS Alias Records because retrieved
records use CamelCase for alias target keys and change_resource_records
required ruby style names. It now accepts both.
have added each of the Route 53 functions
list_hosted_zones is working. rest still need to be tested
[aws|linode|slicehost|zerigo|dns] added complete test cases for linode & slicehost DNS. Also added initial support for AWS Route 53