Add sample file entry into test hash
[Issue #113] Fix service filtering

- Hash.fieldname does not work as expected
- Removed in document check, an error will be thrown and handled if
  requested field is invalid anyway
[Issue #114] Add some rigidity to Hash.hashes

- Hash.hashes is now handled as an embedded field
- Algorithms are now tighter
- Combined hash for each algorithm used is required at the minimum