PacketSender now throws on error. Fixed the documentation on several header files.

examples/traceroute.cpp

@@ -76,6 +76,7 @@ private:
         // ICMPs are icmp-requests by default
         IP ip(addr, iface.addresses().ip_addr, new ICMP());
         // We'll find at most 10 hops.
+        
         for(auto i = 1; i <= 10; ++i) {
             // Set this "unique" id
             ip.id(i);