Remove resets of Aux Selection to fix multi-stream MT writing
For https://its.cern.ch/jira/browse/ATEAM-623
Resetting Aux Selection in one stream would cause other stream to write all attributes. Now selection is only >set< to what it should be. Aux Selection still needs to be identical between streams in MT. To be fixed later(?).
I left some code commented out - need it as a reference for future improvements.
Edited by Marcin Nowak