ioping: New component to measure disk IO latency

This tool can be used to measure disk IO latency for various workloads
(random read, sequential read, direct or cached, write, ...).

We use a bit patched version shows not only avg latency but also its
distribution. (the patches are currently dirty/not very robust and not
yet sent to upstream).

In the upcoming neotest SR ioping will be used to automatically
benchmark underlying disk characteristics.

component/ioping/buildout.cfg

+# ioping - simple disk I/O latency measuring tool
+# https://github.com/koct9i/ioping
+[buildout]
+extends =
+    ../git/buildout.cfg
+
+parts   =
+    ioping
+
+[ioping-repository]
+recipe  = slapos.recipe.build:gitclone
+git-executable = ${git:location}/bin/git
+# NOTE we use a bit patched ioping version which shows not only avg latency but also its distribution
+# repository = https://github.com/koct9i/ioping.git
+repository = https://lab.nexedi.com/kirr/ioping.git
+revision = v1.0-9-g34c97f7636
+
+[ioping]
+recipe  = slapos.recipe.cmmi
+path    = ${ioping-repository:location}
+configure-command = :
+make-binary =
+# XXX without vvv PREFIX=${:location} does not work
+location= ${buildout:parts-directory}/${:_buildout_section_name_}
+make-targets= make install PREFIX=${:location}