Add new scene controller with touch display example.

Upgraded RF24 to latest version which supports SoftSPI. 
Added DigitalIO and UTFT libraries to support the new example.
Fix problem reported in RelayWithButtonActuator example.

libraries/UIPEthernet/utility/mempool.h

@@ -0,0 +1,54 @@
+/*
+ mempool.h - sleek implementation of a memory pool
+ Copyright (c) 2013 Norbert Truchsess <norbert.truchsess@t-online.de>
+ All rights reserved.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef MEMPOOL_H
+#define MEMPOOL_H
+
+#include <inttypes.h>
+
+#define POOLSTART 0
+#define NOBLOCK 0
+
+#include "mempool_conf.h"
+
+struct memblock
+{
+  memaddress begin;
+  memaddress size;
+  memhandle nextblock;
+};
+
+class MemoryPool
+{
+#ifdef MEMPOOLTEST_H
+  friend class MemoryPoolTest;
+#endif
+
+protected:
+  static struct memblock blocks[MEMPOOL_NUM_MEMBLOCKS+1];
+
+public:
+  static void init();
+  static memhandle allocBlock(memaddress);
+  static void freeBlock(memhandle);
+  static void resizeBlock(memhandle handle, memaddress position);
+  static void resizeBlock(memhandle handle, memaddress position, memaddress size);
+  static memaddress blockSize(memhandle);
+};
+#endif