Fix resolv.conf search/nameserver

* Ensure additional nameserver/search, if defined as vars.
* Don't backup changed dhclient hooks as they are going to be
  executed by dhclient as well, which is not what we want.
* For debian OS family only:
- Rename nodnsupdate hook the resolvconf hook to be sourced always
before it.
- Ensure dhclient restarted via network restart to apply the
nodnsupdate hook.
* For rhel OS family, the fix TBD, it doesn't work the same way.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

roles/dnsmasq/defaults/main.yml

@@ -0,0 +1,12 @@
+---
+# Existing search/nameserver resolvconf entries will be purged and
+# ensured by this additional data:
+
+# Max of 4 names is allowed and no more than 256 - 17 chars total
+# (a 2 is reserved for the 'default.svc.' and'svc.')
+#searchdomains:
+#  - foo.bar.lc
+
+# Max of 2 is allowed here (a 1 is reserved for the dns_server)
+#nameservers:
+#  - 127.0.0.1