Refactor SparqlInsert
Add File#described_by
Renamed name_for_dsid to method_name_for_path
Added test for change tracking on properties
Create an IndexingService responsible for indexing resources
Separate the indexing concerns out of the Persistence module
Added File.metadata to define metadata properties
This writes the properties to ./fcr:metadata relative to the files URI
Fixes #499
Merge pull request #582 from projecthydra/with_metadata

With metadata
Merge pull request #584 from projecthydra/solr_indexer_service

Create an IndexingService responsible for indexing resources
Merge pull request #585 from projecthydra/separate_indexing

Separate the indexing concerns out of the Persistence module
Support fixity calls to Fedora

Adds FixityService to ActiveFedora so that a File or any other Fedora
resource can check its fixity.