This MR introduces a new recommendations tag "2019-summer", including:
- TauSelectionTool: implement new electron veto working points
- TauEfficiencyCorrectionsTool: updated systematics for old e-veto working points
- TauEfficiencyCorrectionsTool: new systematics for new e-veto working points
- TauEfficiencyCorrectionsTool: first preliminary systematics for tau decay mode classification
- HelperFunctions: new helper functions to retrieve truth decay mode information
Details on the new electron veto recommendations can be found here: https://its.cern.ch/jira/browse/ATLTAU-1651 Details on the decay mode classification recommendations can be found here: https://its.cern.ch/jira/browse/ATLTAU-1636