BOOST_AUTO_TEST_CASE_TEMPLATE with multiple template types

I find myself with a need to do something like:

```
using test_types_1 std::tuple ;
using test_types_2 = test_types_1;

BOOST_AUTO_TEST_CASE_TEMPLATE( my_test, T1, T2, test_types_1, test_types_2 )
{
BOOST_TEST( sizeof(T1) == sizeof(T2) );
}
```
Where each call to `my_test` is the cross-product of the two vectors of test types.

As well as a need to do

```
using test_types_1 std::tuple ;
using test_types_2 = some_template_type_list;

BOOST_AUTO_TEST_CASE_TEMPLATE( my_test, T1, template T2, test_types_1, test_types_2 )
{
BOOST_TEST( T2.empty() );
}
```

Where the template type provided to BOOST_AUTO_TEST_CASE_TEMPLATE is not fully specified, and is itself a template, so that one of the other template parameter types, or manually written code inside the test, can instantiate the template as part of the test.