Remove unnecessary user defined ctor

there is no reasons defining those probably.

This change allows to be vector trivially copyable iff all elements are
trivially copyable, i.e. following static assert now passes.

```cpp
static_assert(std::is_trivially_copyable<vector<double, int>>{});
```

include/boost/fusion/container/vector/vector.hpp

@@ -131,32 +131,6 @@ namespace boost { namespace fusion
                 : elem() // value-initialized explicitly
             {}
 
-            BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
-            store(store const& rhs)
-                : elem(rhs.elem)
-            {}
-
-            BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
-            store&
-            operator=(store const& rhs)
-            {
-                elem = rhs.elem;
-                return *this;
-            }
-
-            BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
-            store(store&& rhs)
-                : elem(static_cast<T&&>(rhs.elem))
-            {}
-
-            BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
-            store&
-            operator=(store&& rhs)
-            {
-                elem = static_cast<T&&>(rhs.elem);
-                return *this;
-            }
-
             template <
                 typename U
               , typename = typename boost::disable_if<