[3207] A few more minor review changes.

Removed reponse packet type check from IPv6 packet_snd callout.
Corrected text in user chk doxygen page.

src/hooks/dhcp/user_chk/libdhcp_user_chk.dox

@@ -101,9 +101,9 @@ following two entries:
 
     - "type" whose value is "HW_ADDR" for IPv4 users or "DUID" for IPv6 users
     - "id" whose value is either the hardware address or the DUID from the
-    request formatted as a sring of hex digits, with or without ":" delimiters.
+    request formatted as a string of hex digits, with or without ":" delimiters.
 
-and may have the one or more of the following entries:
+and may have the zero or more of the following entries:
 
     - "bootfile" whose value is the pathname of the desired file
     - "tftp_server" whose value is the hostname or IP address of the desired

src/hooks/dhcp/user_chk/pkt_send_co.cc

@@ -149,15 +149,6 @@ int pkt6_send(CalloutHandle& handle) {
         Pkt6Ptr response;
         handle.getArgument("response6", response);
 
-        // @todo Determine list of types to process and skip the rest.
-        uint8_t packet_type = response->getType();
-        if (packet_type == DHCPV6_DECLINE) {
-            std::cout << "DHCP UserCheckHook : pkt6_send"
-                      << "skipping packet type: "
-                      << static_cast<int>(packet_type) << std::endl;
-            return (0);
-        }
-
         // Fetch the lease address as a string
         std::string addr_str = getV6AddrStr(response);
         if (addr_str.empty()) {