Update version history with shared libs changes

Change-Id: Iafd55087bc5eef4c15c3b544222147aa99df7690

docs/source/version_history.rst

diff --git a/docs/source/version_history.rst b/docs/source/version_history.rst
index ba481a6..582c4b9 100644
--- a/docs/source/version_history.rst
+++ b/docs/source/version_history.rst
@@ -35,7 +35,10 @@
 #. Add BlockRandomAccessCRSMatrix.
 #. Speeded up automatic differentiation by 7\%.
 #. Bundle adjustment example from libmv/Blender (Sergey Sharybin)
-#. Add the ability to turn shared library compilation on and off
+#. Shared library building is now controlled by CMake, rather than a custom
+   solution. Previously, Ceres had a custom option, but this is now deprecated
+   in favor of CMake's built in support for switching between static and
+   shared. Turn on BUILD_SHARED_LIBS to get shared Ceres libraries.
 #. No more dependence on Protocol Buffers.
 #. Incomplete LQ factorization.
 #. Ability to write trust region problems to disk.