benchmarks/wrk2: NEW PORT C-based scriptable HTTP load generator

[dch]

Summary

WIP, lua scripting does not yet work with in-tree lua. May need to use included lua,
as its pretty old.

[diizzy]

Given that this seems to be more or less abandoned upstream is this something we need add to the tree?

Aren't any of the follow tools suitable?

benchmarks/plow
benchmarks/bombardier
benchmarks/vegeta
net/oha

There's also https://github.com/fortio/fortio (not ported) which might be of interest

[dch]

dropped