Misc fixes

- changed HEADER_SIZE constant from 8 to 7 to reflect message structure
- removed duplicate utility folder in UIPEthernet that prevented proper
compilation
- removed unnecessary includes in EthernetGateway that prevented proper
compilation

libraries/UIPEthernet/utility/uipethernet-conf.h

@@ -1,18 +0,0 @@
-#ifndef UIPETHERNET_CONF_H
-#define UIPETHERNET_CONF_H
-
-/* for TCP */
-#define UIP_SOCKET_NUMPACKETS    5
-#define UIP_CONF_MAX_CONNECTIONS 4
-
-/* for UDP */
-#define UIP_CONF_UDP             0//1
-#define UIP_CONF_BROADCAST       0//1
-#define UIP_CONF_UDP_CONNS       0//4
-#define UIP_UDP_NUMPACKETS       0//5
-
-/* number of attempts on write before returning number of bytes sent so far
- * set to -1 to block until connection is closed by timeout */
-#define UIP_ATTEMPTS_ON_WRITE    -1
-
-#endif