Remove using namespace std;

For historical reasons we had a "using namespace std;" in port.h. This
is generally a bad idea. So removing it and along the way doing a bunch
of cpplint cleanup.

Change-Id: Ia125601a55ae62695e247fb0250df4c6f86c46c6
diff --git a/internal/ceres/compressed_row_jacobian_writer.h b/internal/ceres/compressed_row_jacobian_writer.h
index a722a7c..517d691 100644
--- a/internal/ceres/compressed_row_jacobian_writer.h
+++ b/internal/ceres/compressed_row_jacobian_writer.h
@@ -33,6 +33,9 @@
 #ifndef CERES_INTERNAL_COMPRESSED_ROW_JACOBIAN_WRITER_H_
 #define CERES_INTERNAL_COMPRESSED_ROW_JACOBIAN_WRITER_H_
 
+#include <utility>
+#include <vector>
+
 #include "ceres/evaluator.h"
 #include "ceres/scratch_evaluate_preparer.h"
 
@@ -80,7 +83,7 @@
   static void GetOrderedParameterBlocks(
       const Program* program,
       int residual_id,
-      vector<pair<int, int> >* evaluated_jacobian_blocks);
+      std::vector<std::pair<int, int> >* evaluated_jacobian_blocks);
 
   // JacobianWriter interface.