Add IP blocking for misbehaving nodes (adapted from Boolberry)

With minor cleanup and fixes (spelling, indent) by moneromooo

src/cryptonote_config.h

@@ -105,6 +105,11 @@
 #define P2P_DEFAULT_HANDSHAKE_INVOKE_TIMEOUT            5000       //5 seconds
 #define P2P_DEFAULT_WHITELIST_CONNECTIONS_PERCENT       70
 
+#define P2P_FAILED_ADDR_FORGET_SECONDS                  (60*60)     //1 hour
+#define P2P_IP_BLOCKTIME                                (60*60*24)  //24 hour
+#define P2P_IP_FAILS_BEFORE_BLOCK                       10
+#define P2P_IDLE_CONNECTION_KILL_INTERVAL               (5*60) //5 minutes
+
 #define ALLOW_DEBUG_COMMANDS
 
 #define CRYPTONOTE_NAME                         "bitmonero"