Title: Added downloadMapper
Description: Added mapper for download, and created methods. Changed and documentMapper and model to fit with new convention.
Edited: model, documentMapper, downloadMapper
Important: Still not tested
Commit: Kasper
Merge remote-tracking branch 'origin/Feature/service/downloads' into Feature/service/downloads
Merge remote-tracking branch 'origin/Feature/service/downloads' into Feature/service/downloads