Multiple bug fixes and few additions
Fixed bug where name was being loaded as IMPLEMENTATION_VERSION instead
of IMPLEMENTATION_TITLE from manifest file.
Added support for "filename" in meta field. This also added the filename
as a key for each Metadata in Artifact.metadata.
Added FieldName class to provide constant field names.
Fixed bug where the hashes were not being correctly structured.
Added combined field to the hashes field.
Renamed HashRecord to Record
Renamed Metadata.fromPom to Metadata.fromPomProperties to reflect what
it is doing.