[dns/scripts] Install utils scripts in INSTALL_EXAMPLE dir (packaging)

This commit install dns scripts to INSTALL_EXAMPLE (in sandbox tree),
for packaging purpose.
Resubmit this abandonned change.
refs: http://lists.opencontrail.org/pipermail/dev_lists.opencontrail.org/2014-July/001226.html

Change-Id: I55a8d81d43a40648606a58805380fde67e7f12d8
(cherry picked from commit 6a5cadaf3a75749d81c0d31b0304b7435f73d124)
Merge "[dns/scripts] Install utils scripts in INSTALL_EXAMPLE dir (packaging)" into R1.06