PyUtils: ROOT6Setup cleanup and add batch mode
Several changes to the PyUtils.Helpers.ROOT6Setup:
- Remove no longer needed Python2 backwards compatibilty code
- Revert XML import workarounds (!31320 (merged),!31424 (merged)) for ATEAM-597 as those are no longer needed in LCG_98.
- With the new PyROOT the command line argument
-bis no longer parsed to set the batch mode. Add an option toROOT6Setupto set batch mode whenever the firstROOTimport is done. This can then be used byathena.pyorathenaHLT.py(ATR-21890) to set the batch mode but without having to actually import ROOT early in the boostrap.
Edited by Atlas Nightlybuild