Create a separate resource class for each ActiveFedora::Base subclass
This ensures that the schemas from different AF::Base subclasses don't
end up merged onto the ActiveTriples::Resource class
Merge pull request #543 from projecthydra/generated_resource_schema

Create a separate resource class for each ActiveFedora::Base subclass
Refactor the associations to follow developments in ActiveRecord
Merge pull request #551 from projecthydra/refactor_associations

Refactor the associations to follow developments in ActiveRecord
Convenience methods from Rubydora

Fedora3-based applications used these methods from Rubydora. We're
including them here to avoid NoMethodError on existing applications
Merge pull request #554 from projecthydra/has_content

Convenience methods from Rubydora
Deprecates usage of #pid in favor of #id.
The method is defined in ActiveFedora::FedoraAttributes and includedin ActiveFedora::Base.
Replaces references to "pid" in other method names and comments with "id".

Closes #407.