bind and mem_fn now support operator== and operator!=

[SVN r21978]

include/boost/bind/bind_template.hpp

@@ -151,6 +151,11 @@
         l_.accept(v);
     }
 
+    bool compare(this_type const & rhs) const
+    {
+        return ref_compare(f_, rhs.f_, 0) && l_ == rhs.l_;
+    }
+
 private:
 
     F f_;