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

internal/ceres/cxsparse.h

@@ -107,8 +107,8 @@ class CXSparse {
   // The returned matrix should be deallocated with Free when not used
   // anymore.
   cs_dis* BlockAnalyzeCholesky(cs_di* A,
-                               const vector<int>& row_blocks,
-                               const vector<int>& col_blocks);
+                               const std::vector<int>& row_blocks,
+                               const std::vector<int>& col_blocks);
 
   // Compute an fill-reducing approximate minimum degree ordering of
   // the matrix A. ordering should be non-NULL and should point to
@@ -133,8 +133,7 @@ typedef void cs_dis;
 
 class CXSparse {
  public:
-  void Free(void*) {};
-
+  void Free(void* arg) {}
 };
 #endif  // CERES_NO_CXSPARSE