[Proposal] Add "SetUp" method

[Mart-Bogdan]

I'd like to add method for user to specify callback to clan resources between runs.

            Script.Of(
                Tuple.Create("sumLinq",   sumLinq),
                Tuple.Create("sumSqLinq", sumSqLinq),
                Tuple.Create("sumSqEvensLinq", sumSqEvenLinq),
                Tuple.Create("cartLinq", cartLinq))
                .SetUp(()=>collection.Reset())
                .RunAll();

Perhaps different methods to run between differnt benchmarks and runs of single Benchmark.