[3274] Changes after review:

- Copyright years updated
 - Minor corrections in BINDX Guide
 - dhcp4.spec relay structure description updated.
 - new unit-test for DHCPv4 client classification added
 - new unit-test for DHCPv6 client classification added
 - fixed Doxygen errors
 - comments for CfgMgr::getSubnet{4,6} updated

src/lib/dhcp/classify.h

@@ -29,9 +29,10 @@
 /// classification is expected to grow significantly.
 ///
 /// @todo This file should be moved to dhcpsrv eventually as the classification
-/// is server side concept. That is not possible yet, as the Pkt4 and Pkt6
-/// classes have server-side implementation, even though they reside in the
-/// dhcp directory.
+/// is server side concept. Client has no notion of classifying incoming server
+/// messages as it usually talks to only one server. That move is not possible
+/// yet, as the Pkt4 and Pkt6 classes have server-side implementation, even
+/// though they reside in the dhcp directory.
 
 namespace isc {
 
@@ -40,23 +41,25 @@ namespace dhcp {
     /// Definition of a single class.
     typedef std::string ClientClass;
 
-    /// Container for storing client classes
+    /// @brief Container for storing client classes
     ///
     /// Depending on how you look at it, this is either a little more than just
     /// a set of strings or a client classifier that performs access control.
     /// For now, it is a simple access list that may contain zero or more
     /// class names. It is expected to grow in complexity once support for
     /// client classes becomes more feature rich.
+    ///
+    /// Note: This class is derived from std::set which may not have Doxygen
+    /// documentation. See  http://www.cplusplus.com/reference/set/set/.
     class ClientClasses : public std::set<ClientClass> {
     public:
-        /// @brief returns if class X belongs to the defined classes
+        /// @brief returns if class x belongs to the defined classes
         ///
         /// @param x client class to be checked
-        /// @return true if X belongs to the classes
+        /// @return true if x belongs to the classes
         bool
         contains(const ClientClass& x) const {
-            const_iterator it = find(x);
-            return (it != end());
+            return (find(x) != end());
         }
     };