Added initial support for dynamic dns zones

dns/templates/zone.dynamic.erb

@@ -0,0 +1,25 @@
+key "<%= zone %>" {
+    algorithm <%= keytype %>;
+    secret "<%= key %>";
+};
+
+zone "<%= zone %>" {
+    type master;
+<% if zone.match(/\//) -%>
+    file "<%= zonedir %>/db.<%= zone.sub(/\//, '-') %>";
+<% else -%>
+    file "<%= zonedir %>/db.<%= zone %>";
+<% end -%>
+    allow-transfer {
+<% if slaves != [] -%>
+<%     slaves.each_pair do |k, v| -%>
+        <%= v['ip'] %>;
+<%     end -%>
+<% else -%>
+        nameservers;
+<% end -%>
+    };
+    allow-update {
+        key <%= zone %>;
+    };
+};