Cartesian product parameters - revisited

[crizzis]

Hello,

It would be a nice feature if we could have the functionality of #135 but independent from the source of parameters (currently, we are forced to use the string approach).

Something along the lines of:

@CombinedParameters({ @Parameters(...), @Parameters(...) })

where the inner Parameters annotations use any strategy to construct the list of parameters (strings, methods, files etc.).