Work around a bug in SWIG_ADD_MODULE

There's a bug in SWIG_ADD_MODULE that breaks out-of-tree builds by not
creating wrapper output directories:
http://www.cmake.org/Bug/view.php?id=14459

Manually create missing directories for the time being to fix the
problem.

References #1

scripting/CMakeLists.txt

@@ -49,6 +49,13 @@ FOREACH(ModName ${CampvisModules})
     ENDIF(CAMPVIS_BUILD_MODULE_${ModNameUpper})
 ENDFOREACH(ModName ${CampvisModules})
 
+# Hack-fix for a bug in SWIG_ADD_MODULE that breaks out-of-tree builds by not creating wrapper
+# output directories.
+# TODO: remove once http://www.cmake.org/Bug/view.php?id=14459 lands
+FOREACH(BindingDir ${CampvisBindingDirs})
+    FILE(MAKE_DIRECTORY "${CMAKE_BINARY_DIR}/${BindingDir}/bindings")
+ENDFOREACH(BindingDir ${CampvisBindingDirs})
+
 
 # Declare a Lua module to be generated by SWIG from the specified interface file
 MACRO(DECLARE_LUA_MODULE InterfaceFile)