Incremental data loading and saving in server mode

[sim642]

Suppose I have done a batch analysis and saved the results using incremental.save. Then currently there's no way to start server mode and load that incremental data I already have. Instead I have to do a full reanalysis in server mode.

Hence, it would be nice if incremental.load work also work together with server mode to load the initial state.

Additionally, it would be beneficial to have server mode requests for loading and saving incremental data at the user's discretion to (re-)load existing incremental data after startup or save satisfactory analysis results for future use.