C++11 ref-qualifier support added

Fixes #1059

Methods with rvalue ref-qualifiers are ignored by default as it is not
possible to have an rvalue temporary from the target language (which is
needed to call the rvalue ref-qualified method).
A warning 405 is shown mentioning the ignored rvalue ref-qualifier method
which can be seen with the -Wextra option.

  cpp_refqualifier.i:15: Warning 405: Method with rvalue ref-qualifier ignored h() const &&.

Usually rvalue and lvalue ref-qualifier overloaded methods are written - the
lvalue method will then be wrapped.

Examples/test-suite/cpp11_ref_qualifiers.i

@@ -0,0 +1,16 @@
+%module cpp11_ref_qualifiers
+
+%inline %{
+class Host {
+public:
+  void h1() & {}
+  void h2() const & {}
+  void h3() && {}
+  void h4() const && {}
+
+  void h() & {}
+  void h() const & {}
+  void h() && {}
+  void h() const && {}
+};
+%}