Updated wxvc_dll.dsp and memory.h to make VC++ compile in DLL mode again

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@5167 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/datetime.h

@@ -376,7 +376,7 @@ public:
 
         // a class representing a time zone: basicly, this is just an offset
         // (in seconds) from GMT
-    class TimeZone
+    class WXDLLEXPORT TimeZone
     {
     public:
         TimeZone(TZ tz);