Fix for build issue with fundamentals-differentiation tutorial code

This MR provides a fix to the build error with the fundamentals-differentiation tutorial code that was occurring when using newer compilers (e.g. on Mac OS Mojave).

The build error no viable overloaded '=' was occurring when trying to assign the result of accessing the PointsManager in the code in tutorials/fundamentals/differentiation/fundamentals-differentiation.

Working with master, building the fundamentals-differentiation tutorial code as part of a full Nektar++ build is successful but a standalone build of the code fails due to C++ 11 support not being enabled. To address this, the fix has been rebased onto the tutorial C++ 11 fix from @ssherw (8f8ed6f9).

fundamentals/differentiation/fundamentals-differentiation/completed/LocDifferentiation2D.cpp

@@ -3,12 +3,11 @@
 
 #include <LibUtilities/Foundations/ManagerAccess.h>
 #include <LibUtilities/Polylib/Polylib.h>
+#include <LibUtilities/LinearAlgebra/NekTypeDefs.hpp>
 
 using namespace Nektar;
 using namespace std;
 
-typedef std::shared_ptr<NekMatrix<NekDouble> > MatrixSharedPtrType;
-
 #define WITHSOLUTION 1
 
 int main(int argc, char *argv[])
@@ -40,8 +39,8 @@ int main(int argc, char *argv[])
 
     // Declare pointers (to type NekMatrix<NekDouble>) to hold the
     // differentiation matrices
-    MatrixSharedPtrType derivMatrixDir1;
-    MatrixSharedPtrType derivMatrixDir2;
+    DNekMatSharedPtr derivMatrixDir1;
+    DNekMatSharedPtr derivMatrixDir2;
 
     // Calculate the GLL-quadrature zeros and the differentiation
     // matrices in both directions. This is done in 2 steps.