Test connecting to virtual function pointer

Test connecting to virtual function pointer

The C++ standard says that the comparison between pointer to virtual
function is unspecified (C++11 $5.10.2)
But we still may rely on it for the Qt::UniqueConnection and the
disconnection

So test if it works while using the same function.
Using function from different classes works for me, but we should
probably not assume it works. I left it commented in the test for
reference.

Change-Id: I1d9b91d4cc1a424d4f43ef2ee4981b8573f1e86f
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>