Enhancement - Path integration

- Implemented Path::operator (std::string) const, to provide an
  automatic cast to std::string for any Path, File or Directory.
- Made use of new cast in various code.
- Changed use of spaces in atoi () calls.
- Switched from std::string::data () to std::string::c_str () calls.

src/tests/path.t.cpp

@@ -1,7 +1,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 // task - a command line task list manager.
 //
-// Copyright 2006 - 2009, Paul Beckingham.
+// Copyright 2006 - 2010, Paul Beckingham.
 // All rights reserved.
 //
 // This program is free software; you can redistribute it and/or modify it under
@@ -33,7 +33,7 @@ Context context;
 
 int main (int argc, char** argv)
 {
-  UnitTest t (31);
+  UnitTest t (32);
 
   // Path ();
   Path p0;
@@ -54,6 +54,9 @@ int main (int argc, char** argv)
   Path p3_copy (p3);
   t.is (p3.data, p3_copy.data, "Path::Path (Path&)");
 
+  // operator (std::string) const;
+  t.is ((std::string) p3, "/tmp", "Path::operator (std::string) const");
+
   // std::string name () const;
   Path p4 ("/a/b/c/file.ext");
   t.is (p4.name (), "file.ext",  "/a/b/c/file.ext name is file.ext");