Sphinx and CMake, based on this example:
   http://ericscottbarr.com/blog/2012/03/sphinx-and-cmake-beautiful-documentation-for-c-projects/

The 'docs/CMakeLists.txt' file was deleted in this commit: 0abfb8f46f534b05413bb4d64b960d6fd0a9befb

Thanks to Arnaud Gelas, he has passed some links:
   https://github.com/InsightSoftwareConsortium/ITKExamples/blob/master/CMake/FindSphinx.cmake
   https://github.com/InsightSoftwareConsortium/ITKExamples/blob/master/CMakeLists.txt#L120-L154

Change-Id: Ic65e7f8ec5280d1e71a897a144417a21761c5553
diff --git a/docs/CMakeLists.txt b/docs/CMakeLists.txt
new file mode 100644
index 0000000..6ebeaf1
--- /dev/null
+++ b/docs/CMakeLists.txt
@@ -0,0 +1 @@
+ADD_SUBDIRECTORY(source)