added file system clean-up of previous build artifacts
Merge pull request #295 from ksclarke/FedoraFileSystemConnectorIT-fs-cleanup-69013802

added file system clean-up of previous build artifacts
Implement Prefer: HTTP headers to control LDPC hierarchy serialization

Resolves: https://www.pivotaltracker.com/story/show/69467742
Updating paging headers and links (next link/header only present when there are more records)

Resolves: https://www.pivotaltracker.com/story/show/69469628
Add ldp:contains predicates for child members of an object