ods: removed default server name

Client is responisble for setting value for before first usage.
Display error msg on entering invalid server url.
ods: added SyncStatusListener for monitoring sync status.
ods: OdsSourceManager forwards calls to SyncStatusListener

For those out there who love design patterns: OdsSourceManager is a
facade.
Added info dialog for displaying sync status
monitor: only copy db on sync success
Minor fix to stop exceptions on emtpy db
levels: minor cleanup
levels: formatted available timestamps
pegelonline: create final instance for convenience