Adjusted CSI example framework for recent changes.
Adjusted CSI example framework for recent changes.

This patch adjusts the CSI example framework for recent cleanups to
example frameworks. It now uses generic flag classes which can e.g.,
parse from both the environment and the command line.

Review: https://reviews.apache.org/r/65042/

reneploetz/mesos,kaysoky/mesos,dforsyth/mesos,reneploetz/mesos,abudnik/mesos,kaysoky/mesos,abudnik/mesos,kaysoky/mesos,dforsyth/mesos,abudnik/mesos,reneploetz/mesos,abudnik/mesos,Gilbert88/mesos,kaysoky/mesos,kaysoky/mesos,abudnik/mesos,abudnik/mesos,dforsyth/mesos,Gilbert88/mesos,dforsyth/mesos,reneploetz/mesos,kaysoky/mesos,dforsyth/mesos,reneploetz/mesos,Gilbert88/mesos,dforsyth/mesos,Gilbert88/mesos,Gilbert88/mesos,Gilbert88/mesos,reneploetz/mesos,dforsyth/mesos,kaysoky/mesos,abudnik/mesos,reneploetz/mesos,Gilbert88/mesos