Update to Eigen 3.3.7

CMake/SuperBuild.cmake

@@ -9,7 +9,7 @@ else()
         ExternalProject_Add(EIGEN
 	    GIT_REPOSITORY "https://github.com/eigenteam/eigen-git-mirror.git"
 	    UPDATE_COMMAND "" 
-	    GIT_TAG "3.3.5" #"default"
+	    GIT_TAG "3.3.7" #"default"
    	    PREFIX ${CMAKE_CURRENT_BINARY_DIR}/external/eigen
    	    CMAKE_ARGS -DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_INSTALL_PREFIX}
 		#CONFIGURE_COMMAND ""