Petter's MSVC fixes

Change-Id: I13a2f6e1046136ce240c22dadd1b7547f56d4493
diff --git a/internal/ceres/coordinate_descent_minimizer.cc b/internal/ceres/coordinate_descent_minimizer.cc
index 72edfe2..d85601d 100644
--- a/internal/ceres/coordinate_descent_minimizer.cc
+++ b/internal/ceres/coordinate_descent_minimizer.cc
@@ -30,6 +30,7 @@
 
 #include "ceres/coordinate_descent_minimizer.h"
 
+#include <iterator>
 #include <numeric>
 #include <vector>
 #include "ceres/evaluator.h"