I wasn't being able to compile the project on CentOS 7.5 with cmake because of a missing condition in the src/C++/Utility.h file.

This PR fixes two things:

• A wrong HAVE_STD_TR1_SHARED_PTR condition where it was including <tr1/memory> instead of just <memory>
• Adds the missing HAVE_STD_TR1_SHARED_PTR_FROM_TR1_MEMORY_HEADER condition to include <tr1/memory> and use the namespace ptr = std::tr1

The solution is based on the content of the file cmake/FindSharedPtr.cmake:

This is the condition to set the HAVE_STD_TR1_SHARED_PTR variable:

check_cxx_source_compiles("#include <memory>
                           int main() {
                             std::shared_ptr<int> int_ptr;
                             return 0;
                           }"
                          HAVE_SHARED_PTR_IN_STD_NAMESPACE)

And this is the one to set HAVE_STD_TR1_SHARED_PTR_FROM_TR1_MEMORY_HEADER:

check_cxx_source_compiles("#include <tr1/memory>
                           int main() {
                             std::tr1::shared_ptr<int> int_ptr;
                             return 0;
                           }"
                          HAVE_SHARED_PTR_IN_TR1_NAMESPACE_FROM_TR1_MEMORY_HEADER)