ENH: Addition of ctk_cli

ctk_cli [1] is a command line parsing python package that parses
arguments the same way SlicerExecutionModel does.
Using ctk_cli allows in Python scripts allows to have the same
user interface in Python or in C++.

[1] https://github.com/commontk/ctk-cli

Author: fbudin69500

SuperBuild.cmake

@@ -100,7 +100,7 @@ if(Slicer_USE_SimpleITK)
 endif()
 
 if(Slicer_BUILD_CLI_SUPPORT)
-  list(APPEND Slicer_DEPENDENCIES SlicerExecutionModel)
+  list(APPEND Slicer_DEPENDENCIES SlicerExecutionModel python-ctk_cli)
 endif()
 
 if(Slicer_BUILD_EXTENSIONMANAGER_SUPPORT)

SuperBuild/External_python-ctk_cli.cmake

@@ -0,0 +1,36 @@
+set(proj python-ctk_cli)
+
+# Set dependency list
+set(${proj}_DEPENDENCIES python python-setuptools)
+
+# Include dependent projects if any
+ExternalProject_Include_Dependencies(${proj} PROJECT_VAR proj DEPENDS_VAR ${proj}_DEPENDENCIES)
+
+if(${CMAKE_PROJECT_NAME}_USE_SYSTEM_${proj})
+  # XXX - Add a test checking if <proj> is available
+endif()
+
+if(NOT DEFINED ${CMAKE_PROJECT_NAME}_USE_SYSTEM_${proj})
+  set(${CMAKE_PROJECT_NAME}_USE_SYSTEM_${proj} ${${CMAKE_PROJECT_NAME}_USE_SYSTEM_python})
+endif()
+
+set(ctk_cli_REPOSITORY ${git_protocol}://github.com/commontk/ctk-cli.git)
+set(ctk_cli_GIT_TAG 4346a22618b299c8eff84c6a179067ca68db43b9)
+
+if(NOT ${CMAKE_PROJECT_NAME}_USE_SYSTEM_${proj})
+
+  ExternalProject_Add(${proj}
+    ${${proj}_EP_ARGS}
+    GIT_REPOSITORY ${ctk_cli_REPOSITORY}
+    GIT_TAG ${ctk_cli_GIT_TAG}
+    SOURCE_DIR ${proj}
+    BUILD_IN_SOURCE 1
+    CONFIGURE_COMMAND ""
+    BUILD_COMMAND ""
+    INSTALL_COMMAND ${PYTHON_EXECUTABLE} setup.py install
+    DEPENDS
+      ${${proj}_DEPENDENCIES}
+    )
+else()
+  ExternalProject_Add_Empty(${proj} DEPENDS ${${proj}_DEPENDENCIES})
+endif()