DATACMNS-90 - Allow Repository namespace handler to be configured to scan for inner class repositories.

We now optionally consider nested repository interfaces defined as inner-classes. This can be configured by setting the considerNestedRepositories property on EnableXXXRepository annotations or the consider-nested-repositories attribute to true - it defaults to false.

Original pull request: #50.
DATACMNS-90 - Polishing.

Added missing author tags where needed. Removed the template method to pick up the configuration from the RepositoryConfigurationSource interface as it's not needed from the outside.

Original pull request: #50.