Add failover and health check attributes
Don't nuke attributes on ResourceRecordSet update

Previously, if you were not changing the name, type, or set identifier, they
would be destructively removed from the ResourceRecordSet on update.
Merge pull request #292 from zenazn/nuke

Don't nuke attributes on ResourceRecordSet update
Merge pull request #294 from tongueroo/master

add AWS.reset_memoization method
Merge pull request #293 from zenazn/new_attrs

Add failover and health check attributes
Added whitespace in client documentation to ensure nested lists render correctly.
Updated client API documentation for both Amazon DynamoDB clients.
Each service now hash a top-level configuration entry.

Each service now has a config option, for example:

    AWS.config.s3
    #=> {}

You can specify the value like any other configuration option:

    AWS.config(:s3 => { 'abc' => 'xyz' })

These values are not yet used anywhere.  They will eventually
be merged with the root level configuration options when building
a client.
You can now specify endpoint, region and port per service via AWS.config(:svc => { ... })

You can specify global options per service now using the new configuration options.
Example:

    AWS.config(:s3 => { :region => 'us-west-2' })

    AWS::S3.new.config.s3_region
    #=> 'us-west-2'
Renamed helper methods for AWS::SimpleEmailService and AWS::SimpleWorkflow.

To be consistent with other services that use the official service abbreviation,
the helper methods on `AWS` and `AWS::Core::Region` now use the short names for
`AWS::SimpleEmailService` and `AWS::SimpleWorkflow`.

    # new methods
    AWS.ses
    AWS.swf
    AWS.regions['us-west-2'].ses
    AWS.regions['us-west-2'].swf

    # deprecated methods
    AWS.simple_email_service
    AWS.simple_workflow
    AWS.regions['us-west-2'].simple_email_service
    AWS.regions['us-west-2'].simple_workflow

Additionally global configuration options use the short name.

    AWS.config(:ses => {...})
    AWS.config(:swf => {...})
Updated documentation for service helpers.
Updated specs to use the new AWS::SERVICES format.
Allow setting hash_key to values other than id
Allow setting hash_key

When creating the dynamo_db_table instance the hash_key defaults to id.
This patch allows assigning a string attribute as the id.
Fix bug with hash_key
Merge pull request #295 from aws/service-specific-configuration

Add service specific options to AWS.config
Added support for watermarks to AWS::ElasticTranscoder::Client.
Fixed the copyright dates in two files.
Bump version to 1.12.0
AWS::DynamoDB::Client now supports both Amazon DynamoDB API versions.

`AWS::DynamoDB::ClientV2` is now deprecated.  Instead of using this class, you can
construct a client of a specific version like so:

    ddb = AWS::DynamoDB::Client.new(:api_version => '2012-08-10')

Constructing a client without an API version returns a client of the oldest
version.  This ensures existing users of AWS::DynamoDB::Client will not experience
runtime errors from the differences.

This works by turning AWS::DynamoDB::Client.new into a factory method.  It returns
an instance of Client::V20111005 or Client::V20120810 based on the :api_version
option.