Merge pull request #42 from cap257zero/master

Changes in "file_dialog_open.cpp" and "file_dialog_save.cpp" to help compilation in Vista

Former-commit-id: ac7818e87545767f3c5e5375d5f84d43f71dee16

include/igl/file_dialog_open.cpp

@@ -32,7 +32,7 @@ IGL_INLINE std::string igl::file_dialog_open()
   while ( fgets(buffer, FILE_DIALOG_MAX_BUFFER, output) != NULL )
   {
   }
-#elif _WIN32
+#elif defined _WIN32
   
   // Use native windows file dialog box
   // (code contributed by Tino Weinkauf)

include/igl/file_dialog_save.cpp

@@ -34,7 +34,7 @@ IGL_INLINE std::string igl::file_dialog_save()
   while ( fgets(buffer, FILE_DIALOG_MAX_BUFFER, output) != NULL )
   {
   }
-#elif _WIN32
+#elif defined _WIN32
 
   // Use native windows file dialog box
   // (code contributed by Tino Weinkauf)