[D] Fixed referencing types in the root namespace when not in split proxy mode.

Previously, invalid code would be generated for cases like the following if the nspace feature was active, but the split proxy mode not:
---
struct Foo {};
namespace Ns {
  struct Bar {
    void bar(const Foo &f) {}
  };
}
---

Thanks to Johannes Pfau for reporting this.

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@12629 626c5289-ae23-0410-ae9c-e8d60b6d4f22

CHANGES.current

@@ -4,6 +4,9 @@ See the RELEASENOTES file for a summary of changes in each release.
 
 Version 2.0.4 (in progress)
 ===========================
+2011-04-10: klickverbot
+            [D] nspace: Fixed referencing types in the root namespace when
+            not in split proxy mode.
 
 2011-04-07: wsfulton
             Fix wrapping of const array typedefs which were generating uncompileable code as