Code Migration

- Migrated taskd JSON parser into task, to provide encode/decode
  capability to Task::composeJSON.
- Migrated taskd utf8 code, replacing old unused code.
- Added unit tests or JSON.
- Migrated Tree updates from taskd.

src/JSON.h

@@ -0,0 +1,61 @@
+////////////////////////////////////////////////////////////////////////////////
+// taskwarrior - a command line task list manager.
+//
+// Copyright 2010 - 2011, Paul Beckingham, Federico Hernandez.
+// 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 2 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, write to the
+//
+//     Free Software Foundation, Inc.,
+//     51 Franklin Street, Fifth Floor,
+//     Boston, MA
+//     02110-1301
+//     USA
+//
+////////////////////////////////////////////////////////////////////////////////
+#ifndef INCLUDED_JSON
+#define INCLUDED_JSON
+
+#include <string>
+#include <Tree.h>
+#include <Nibbler.h>
+
+class JSON
+{
+public:
+  JSON ();                       // Default constructor
+  JSON (const std::string&);     // Constructor
+  JSON (const JSON&);            // Copy constructor
+  JSON& operator= (const JSON&); // Assignment operator
+  ~JSON ();                      // Destructor
+
+  static std::string encode (const std::string&);
+  static std::string decode (const std::string&);
+
+  Tree* tree ();
+
+private:
+  bool parseObject (Tree*, Nibbler&);
+  bool parsePair (Tree*, Nibbler&);
+  bool parseArray (Tree*, Nibbler&);
+  bool parseValue (Tree*, Nibbler&);
+  bool parseString (Tree*, Nibbler&);
+  bool parseNumber (Tree*, Nibbler&);
+
+private:
+  Tree root;
+};
+
+#endif
+////////////////////////////////////////////////////////////////////////////////