Revert "utils/function: expose also ref and cref"

Visual studio 9.0 (2008) and 2012 work, but 2010 breaks :(

This reverts commit 0b90d7930804beb2f0a16e97b75a6e8fd9a2b835

Change-Id: I3c9bea05ac07ca8cdeb5be5fb89234675dd72061
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>

src/libs/utils/function.cpp

@@ -41,7 +41,7 @@ void functionUser(Utils::function<int()> generator, Utils::function<void(int)> c
 
 struct GenFunctor
 {
-    int operator()() const { return 29; }
+    int operator()() { return 29; }
 };
 
 struct ConsumerFunctor
@@ -49,13 +49,6 @@ struct ConsumerFunctor
     void operator()(int) {}
 };
 
-struct ConsumerFunctor2
-{
-    ConsumerFunctor2() : i(0) { }
-    int i;
-    void operator()(int j) { i = j; }
-};
-
 int generatorF()
 {
     return 42;
@@ -71,9 +64,6 @@ void test()
 {
     functionUser(GenFunctor(), ConsumerFunctor());
     functionUser(&generatorF, &consumerF);
-    ConsumerFunctor2 f2;
-    GenFunctor g2;
-    functionUser(Utils::cref(g2), Utils::ref(f2));
 }
 
 } // end namespace