• new way to specify parameters for predictors. Now, instead of USING {JSON} prefer way will be: USING key=value, another_key.subkey={JSON}, etc
• beta feature: views.
  Create view:
  create view view_name from datasource_name (select * from table);
  List views:
  show views;
  Create predictor from view:
  create predictor predictor_name from views (select * from vies_name) predict column_name
• beta feature: now possible train predictors from files:
  create predictor predictor_name from files (select * from file_name) predict column_name
• returning correct error codes for sql exceptions (previously we always returned 'syntax error' code on any error)
• fix: TS predictions for multiple groups now return correct result