[microbench] Upgrade JMH to 0.4.1 and make use of @Params.

I dont want to upgrade all the time, but we got @Params support which makes it look so much nicer :)

```
Benchmark                                                      (size)   Mode   Samples         Mean   Mean error    Units
i.n.m.b.ByteBufAllocatorBenchmark.pooledDirectAllocAndFree      00000  thrpt         2    12306.120          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledDirectAllocAndFree      00256  thrpt         2    10978.065          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledDirectAllocAndFree      01024  thrpt         2     9669.683          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledDirectAllocAndFree      04096  thrpt         2     6535.983          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledDirectAllocAndFree      16384  thrpt         2     6732.000          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledDirectAllocAndFree      65536  thrpt         2     6714.374          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledHeapAllocAndFree        00000  thrpt         2    11720.884          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledHeapAllocAndFree        00256  thrpt         2    10056.961          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledHeapAllocAndFree        01024  thrpt         2     8544.572          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledHeapAllocAndFree        04096  thrpt         2     6446.857          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledHeapAllocAndFree        16384  thrpt         2     6633.493          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.pooledHeapAllocAndFree        65536  thrpt         2     6433.788          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledDirectAllocAndFree    00000  thrpt         2     2200.349          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledDirectAllocAndFree    00256  thrpt         2     1827.377          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledDirectAllocAndFree    01024  thrpt         2     1992.389          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledDirectAllocAndFree    04096  thrpt         2     1606.827          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledDirectAllocAndFree    16384  thrpt         2      868.110          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledDirectAllocAndFree    65536  thrpt         2      284.873          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledHeapAllocAndFree      00000  thrpt         2    33790.695          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledHeapAllocAndFree      00256  thrpt         2    20015.072          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledHeapAllocAndFree      01024  thrpt         2     6268.291          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledHeapAllocAndFree      04096  thrpt         2     2836.629          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledHeapAllocAndFree      16384  thrpt         2     1072.343          NaN   ops/ms
i.n.m.b.ByteBufAllocatorBenchmark.unpooledHeapAllocAndFree      65536  thrpt         2      274.864          NaN   ops/ms
```