Code Salvage

- Integrated some code from the (soon to be obsolete) 2.0.0 branch,
  which is general in nature and will be needed.
- And the corresponding unit tests.

src/Sensor.h

@@ -0,0 +1,59 @@
+////////////////////////////////////////////////////////////////////////////////
+// taskwarrior - a command line task list manager.
+//
+// Copyright 2010, 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_SENSOR
+#define INCLUDED_SENSOR
+
+#include <string>
+
+class Sensor
+{
+public:
+  Sensor ();
+  ~Sensor ();
+  Sensor (const Sensor&);
+  Sensor& operator= (const Sensor&);
+
+  bool changed ();
+  void reset ();
+
+//  void fileCreation     (const std::string&);
+  void fileModification (const std::string&);
+//  void fileDeletion     (const std::string&);
+
+private:
+  time_t getModification ();
+
+private:
+  bool        _changed;
+  std::string _file;
+  time_t      _was;
+  time_t      _is;
+};
+
+#endif
+
+////////////////////////////////////////////////////////////////////////////////