Reconstruction/tau: cmake cleanup, enable flake8

cmake cleanup for tau reconstruction packages. Most minor fixes. The biggest change is in tauRec where all private headers got moved to the src directory and the python code was made flake8 compliant.

Reconstruction/DiTauRec/CMakeLists.txt

-################################################################################
-# Package: DiTauRec
-################################################################################
+# Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 
 # Declare the package name:
 atlas_subdir( DiTauRec )
 
-# Declare the package's dependencies:
-atlas_depends_on_subdirs( PUBLIC
-                          Control/AthenaBaseComps
-                          Event/xAOD/xAODEgamma
-                          Event/xAOD/xAODJet
-                          Event/xAOD/xAODMuon
-                          Event/xAOD/xAODTau
-                          GaudiKernel
-                          PhysicsAnalysis/MuonID/MuonSelectorTools
-                          Reconstruction/Jet/JetEDM
-                          Tracking/TrkTools/TrkToolInterfaces
-                          PRIVATE
-                          Calorimeter/CaloEvent
-                          Event/xAOD/xAODTracking
-                          Reconstruction/RecoTools/RecoToolInterfaces
-                          Reconstruction/tauRecTools
-                          Tracking/TrkEvent/TrkParametersIdentificationHelpers )
-
 # External dependencies:
 find_package( FastJet )
 
@@ -31,9 +11,8 @@ atlas_add_component( DiTauRec
                      src/*.cxx
                      src/components/*.cxx
                      INCLUDE_DIRS ${FASTJET_INCLUDE_DIRS}
-                     LINK_LIBRARIES ${FASTJET_LIBRARIES} AthenaBaseComps xAODEgamma xAODJet xAODMuon xAODTau GaudiKernel MuonSelectorToolsLib JetEDM TrkToolInterfaces CaloEvent xAODTracking RecoToolInterfaces tauRecToolsLib TrkParametersIdentificationHelpers )
+                     LINK_LIBRARIES ${FASTJET_LIBRARIES} AthenaBaseComps xAODEgamma xAODJet xAODMuon xAODTau GaudiKernel JetEDM TrkToolInterfaces CaloEvent xAODTracking RecoToolInterfaces StoreGateLib tauRecToolsLib TrkParametersIdentificationHelpers )
 
 # Install files from the package:
-atlas_install_headers( DiTauRec )
 atlas_install_python_modules( python/*.py POST_BUILD_CMD ${ATLAS_FLAKE8} )
 atlas_install_joboptions( share/*.py POST_BUILD_CMD ${ATLAS_FLAKE8} --extend-ignore=F401,F821 )