Radargun 2.0

I won't describe all of the changes here, see each commit message.

I can't say that everything was tested - probably, it will take quite some time to hunt down all the bugs I've introduced. Scripts bin/dist.sh and bin/local.sh should run working benchmark, so that users trying out RadarGun see the basics.

Therefore, this PR is rather for reference and get you acquainted with the new concepts. If you spot any problem, please, report it and we'll add commit fixing them.