synchronization
Merge pull request #40 from lukaselmer/synchronization-part-3

synchronization
refactoring
refactoring
refactoring
enhance service
refactoring, service
create disk
service
update service reference
implemented synchronize local changes to server
implement synchronization to the local system
implement synchronization service
synchronization server
remove user service, add disk service
implement sqlite persistence
sqlite
remove sqlite file
Merge pull request #41 from lukaselmer/synchronization-part-5

Synchronization part 5
added autogenerated ids, enable authentication