Initial commit:

1) Introduce WritableRepository interface as a method of allowing for a repository to define how to push items instead of just being able to pull them.
2) Create S3Repository that implements WritableRepository and works off stuff existing in an s3 bucket somewhere
3) Introduce CoordinatorConfigProxyResource which is a simple resource that allows for the getting of configs.  It will also allow for the setting if the Repository instance implements WritableRepository
4) Some stuff to make it Guice inject, I think...