Merge branch 'evelu-exec' of https://github.com/ErwanAliasr1/fio

* 'evelu-exec' of https://github.com/ErwanAliasr1/fio:
  fiograph: Adding exec engine support
  engines: Adding exec engine

diff --cc HOWTO
Simple merge

diff --cc Makefile
Simple merge

diff --cc fio.1
Simple merge