Improved support for Visual C++.

[SVN r2985]

test/container/link_test_1.cpp

@@ -19,4 +19,6 @@ int main()
     boost::unordered_multimap<int, int> x4;
 
     foo(x1, x2, x3, x4);
+    
+    return 0;
 }

test/container/simple_tests.cpp

@@ -58,7 +58,7 @@ void simple_test(X const& a)
 
     {
         X u;
-        X& r(u);
+        X& r = u;
         // TODO: I can't actually see a requirement for that assignment
         // returns a reference to itself (just that it returns a reference).
         BOOST_TEST(&(r = r) == &r);