[master] Added ChangeLog entry for #2977.

ChangeLog

@@ -1,3 +1,10 @@
+640.	[func]		marcin
+	b10-dhcp-ddns: Implemented DNSClient class which implements
+	asynchronous DNS updates using UDP. The TCP and TSIG support
+	will be	implemented at later time. Nevertheless, class API
+	accomodates the use of TCP and TSIG.
+	(Trac #2977, git 5a67a8982baa1fd6b796c063eeb13850c633702c)
+
 639.	[bug]		muks
 	Added workaround for build failure on Fedora 19 between GCC 4.8.x
 	and boost versions less than 1.54. Fedora 19 currently ships