Benchmark script takes host, port args
Merge pull request #1 from avieth/aovieth/benchmark_args

Benchmark script takes host, port args
Do benchmark using mapConcurrently
Refactor benchmarks to use criterion
Update benchmark build-depends
Merge pull request #2 from avieth/aovieth/benchmark

Benchmarking: use criterion, remove concurrency
Use BlockBuffering on socket handle

This improves pipelining performance. Without BlockBuffering, the handle
defaults to NoBuffering, and every hPut is immediately digested, i.e.
the hFlush in the unsafeInterleaveIO section never actually does
anything!