Data driven test cases: customizing test names and decorators

Hi,

Is it possible to customize the test names generated by the data-driven test case macros (`BOOST_DATA_TEST_CASE`)? In Google Test, you can do:

```
INSTANTIATE_TEST_SUITE_P(InstantiationName, TestSuiteName, Values(
/* dataset here */
), test_name_generator);
```
Where `test_name_generator` is a function that takes as argument a wrapped sample and returns a string with the name the test should have. That replaces the "_0", "_1"... generated by default. So your test names would be something like:
- `InstantiationName/TestSuiteName/Name1`
- `InstantiationName/TestSuiteName/Name2`

Assuming `test_name_generator` would return `Name1` and `Name2` for the two samples of the dataset.

Is there something similar available in Boost.Test? If there is not, what would be the equivalent using manual test registration? All these tests do use fixtures. I would also need to apply different labels depending on the sample.

Many thanks.