Modified some examples fixed some doxygen documentation.

include/ip.h

@@ -333,13 +333,6 @@ namespace Tins {
 
         /* Setters */
 
-        /**
-         * \brief Setter for the header length field.
-         *
-         * \param new_head_len The new header length.
-         */
-        void head_len(small_uint<4> new_head_len);
-
         /**
          * \brief Setter for the type of service field.
          *
@@ -347,13 +340,6 @@ namespace Tins {
          */
         void tos(uint8_t new_tos);
 
-        /**
-         * \brief Setter for the total length field.
-         *
-         * \param new_tot_len The new total length.
-         */
-        void tot_len(uint16_t new_tot_len);
-
         /**
          * \brief Setter for the id field.
          *
@@ -618,6 +604,10 @@ namespace Tins {
             /*The options start here. */
         } TINS_END_PACK;
 
+
+        void head_len(small_uint<4> new_head_len);
+        void tot_len(uint16_t new_tot_len);
+
         void prepare_for_serialize(const PDU *parent);
         void internal_add_option(const option &option);
         void init_ip_fields();

include/packet_sender.h

@@ -76,6 +76,7 @@ namespace Tins {
         /**
          * \brief Constructor for PacketSender objects.
          * 
+         * \param iface The default interface in which to send the packets.
          * \param recv_timeout The timeout which will be used when receiving responses.
          */
         PacketSender(const NetworkInterface &iface = NetworkInterface(), 
@@ -168,7 +169,7 @@ namespace Tins {
          * 
          * \sa PacketSender::default_interface
          */
-        const NetworkInterface& default_interface();
+        const NetworkInterface& default_interface() const;
 
         /** 
          * \brief Sends a PDU. 

include/pdu.h

@@ -118,7 +118,8 @@ namespace Tins {
             DOT1Q,
             PPPOE,
             STP,
-            PPI
+            PPI,
+            USER_DEFINED_PDU = 1000
         };
 
         /** 

include/sniffer.h

@@ -103,7 +103,7 @@ namespace Tins {
         /**
          * \brief Compiles a filter and uses it to capture one packet.
          * 
-         * This method returns the first sniffed packet that matches the 
+         * This method returns the first valid sniffed packet that matches the 
          * sniffer's filter, or the first sniffed packet if no filter has
          * been set.
          * 
@@ -123,39 +123,36 @@ namespace Tins {
          * \code
          * // bad!!
          * PtrPacket p = s.next_packet();
-         * 
          * \endcode
          * 
          * Is not, since PtrPacket can't be copy constructed. 
          * 
          * \sa Packet::release_pdu
          * 
-         * \return The captured packet, matching the given filter.
-         * If an error occured(probably compiling the filter), PtrPacket::pdu
-         * will return 0. Caller takes ownership of the PDU * stored in
+         * \return A captured packet. If an error occured, PtrPacket::pdu 
+         * will return 0. Caller takes ownership of the PDU pointer stored in 
          * the PtrPacket.
          */
         PtrPacket next_packet();
         
         /**
-         * \brief Starts a sniffing loop, using a callback object for every
+         * \brief Starts a sniffing loop, using a callback functor for every
          * sniffed packet.
          * 
-         * The callback object must implement an operator with one of the 
+         * The functor must implement an operator with one of the 
          * following signatures:
          * 
          * \code
-         * bool operator()(PDU&);
-         * bool operator()(const PDU&);
+         * bool(PDU&);
+         * bool(const PDU&);
          * \endcode
          * 
-         * This operator will be called using the sniffed packets 
-         * as arguments. You can modify the parameter argument as you wish. 
-         * Calling PDU methods like PDU::release_inner_pdu is perfectly 
-         * valid.
+         * This functor will be called using the each of the sniffed packets 
+         * as its argument. Using PDU member functions that modify the PDU,
+         * such as PDU::release_inner_pdu, is perfectly valid.
          * 
-         * Note that the Functor object will be copied using its copy
-         * constructor, so that object should be some kind of proxy to
+         * Note that if you're using a functor object, it will be copied using 
+         * its copy constructor, so it should be some kind of proxy to
          * another object which will process the packets(e.g. std::bind).
          *
          * Sniffing will stop when either max_packets are sniffed(if it is != 0), 

include/tcp.h

@@ -201,14 +201,6 @@ namespace Tins {
          */
         const options_type &options() const { return _options; }
 
-        /**
-         * \brief Gets the value of a flag.
-         * 
-         * \param tcp_flag The polled flag.
-         * \return The value of the flag.
-         */
-        small_uint<1> get_flag(Flags tcp_flag);
-
         /**
          * \brief Gets the value of a flag.
          *