Revert "Merge branch 'pyfwdbwd' into 'master'"

This reverts merge request !22075

External/AtlasPyFwdBwdPorts/CMakeLists.txt

+# $Id: CMakeLists.txt 790212 2016-12-16 17:43:15Z ssnyder $
 
 # The name of the package:
 atlas_subdir( AtlasPyFwdBwdPorts )
@@ -100,7 +101,13 @@ _setup_python_package( pyflakes
 _setup_python_package( flake8
    ${CMAKE_CURRENT_SOURCE_DIR}/src/flake8-3.6.0.tar.gz
    178485aed0799655d0cbf2e3bdcfaddc
-   DEPENDS pyflakes pycodestyle mccabe
+   DEPENDS pyflakes pycodestyle mccabe enum34
+   SINGLE_VERSION )
+
+# Install enum34:
+_setup_python_package( enum34
+   ${CMAKE_CURRENT_SOURCE_DIR}/src/enum34-1.1.6.tar.gz
+   5f13a0841a61f7fc295c514490d120d0
    SINGLE_VERSION )
 
 # Install mccabe: