Faceteer Converter

This is a clone of the AWS.DynamoDB.Converter class.

It was created to allow Faceteer to be able to convert to and from Dynamo DB objects without requiring the installation of the aws-sdk.

It also adds functionality for handling Date values when converting to a Dynamo DB object. By default dates are converted to an ISO string, but they may be converted to a Unix timestamp by overriding the converter options.