Explicitly delete all non implemented assignment operators.

Commit (almost) automatically generated with the following sed command:
sed -i -ne '1h;1!H;${g;s|\n[[:blank:]]*private:\n\([[:blank:]]*\)// silence MSVC warning C4512: assignment operator could not be generated\n\([[:blank:]]*\)\([^\n]\+\);\n|\n\1// silence MSVC warning C4512: assignment operator could not be generated\n\2BOOST_DELETED_FUNCTION(\3)\n|g;p}' $(git ls-files)

include/boost/fusion/container/deque/deque_iterator.hpp

@@ -111,9 +111,8 @@ namespace boost { namespace fusion {
 
         Seq& seq_;
 
-    private:
         // silence MSVC warning C4512: assignment operator could not be generated
-        deque_iterator& operator= (deque_iterator const&);
+        BOOST_DELETED_FUNCTION(deque_iterator& operator= (deque_iterator const&))
     };
 
 }}

include/boost/fusion/container/list/cons_iterator.hpp

@@ -42,9 +42,8 @@ namespace boost { namespace fusion
 
         cons_type& cons;
 
-    private:
         // silence MSVC warning C4512: assignment operator could not be generated
-        cons_iterator& operator= (cons_iterator const&);
+        BOOST_DELETED_FUNCTION(cons_iterator& operator= (cons_iterator const&))
     };
 
     struct nil_iterator : iterator_base<nil_iterator>

include/boost/fusion/container/map/map_iterator.hpp

@@ -156,9 +156,8 @@ namespace boost { namespace fusion
 
         Seq& seq_;
 
-    private:
         // silence MSVC warning C4512: assignment operator could not be generated
-        map_iterator& operator= (map_iterator const&);
+        BOOST_DELETED_FUNCTION(map_iterator& operator= (map_iterator const&))
     };
 
 }}

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

@@ -43,9 +43,8 @@ namespace boost { namespace fusion
 
         Vector& vec;
 
-    private:
         // silence MSVC warning C4512: assignment operator could not be generated
-        vector_iterator& operator= (vector_iterator const&);
+        BOOST_DELETED_FUNCTION(vector_iterator& operator= (vector_iterator const&))
     };
 }}