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/scripts/make_release b/scripts/make_release
index 36643e9..d3ca820 100755
--- a/scripts/make_release
+++ b/scripts/make_release
@@ -40,9 +40,9 @@
 
 TMP="/tmp/ceres-solver-$1"
 DOCS_TMP="/tmp/ceres-solver-docs-$1"
-VERSION=$(grep 'SET(CERES_VERSION' CMakeLists.txt | \
-          sed -e 's/SET(CERES_VERSION //' | \
-          sed -e 's/)//')
+VERSION=$(grep 'SET(CERES_VERSION_' CMakeLists.txt | \
+          sed -e 's/\(.*\) \(.*\))/\2/' | \
+          tr '\n' '.' | sed -e 's/.$//')
 ABI_VERSION=$(grep 'SET(CERES_ABI_VERSION' CMakeLists.txt | \
               sed -e 's/SET(CERES_ABI_VERSION //' | \
               sed -e 's/)//')
@@ -89,9 +89,8 @@
   exit 1
 fi
 
-# Clone the repository and clean out the git extras.
-git clone . $TMP
-rm -rf "$TMP/.git"
+# Export repository.
+git checkout-index -f -a --prefix=$TMP/
 
 # Build the VERSION file.
 VERSIONFILE=$TMP/VERSION