Added regular expression support

- Added rx.{h,cpp} from Tegelsten.
- Added unit tests.

src/rx.h

@@ -0,0 +1,39 @@
+////////////////////////////////////////////////////////////////////////////////
+// task - 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_RX
+#define INCLuDED_RX
+
+#include <string>
+#include <vector>
+
+bool regexMatch (const std::string&, const std::string&, bool caseSensitive = true);
+bool regexMatch (std::vector<std::string>&, const std::string&, const std::string&, bool caseSensitive = true);
+bool regexMatch (std::vector<int>&, std::vector<int>&, const std::string&, const std::string&, bool caseSensitive = true);
+
+#endif
+