Bug Fix - due date, colorization

- Fixed bug that caused colorization to be way, way off.  Silly
  mistake.
- Fixed bug whereby due dates and durations were stored as-is, but
  should have been converted.
- On a related note, added Date::toEpochString,
  Duration::operator (std::string).

src/Duration.cpp

@@ -25,6 +25,8 @@
 //
 ////////////////////////////////////////////////////////////////////////////////
 
+#include <sstream>
+#include <string>
 #include <vector>
 #include <stdlib.h>
 #include "text.h"
@@ -55,6 +57,14 @@ Duration::operator time_t ()
   return mDays;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+Duration::operator std::string ()
+{
+  std::stringstream s;
+  s << mDays;
+  return s.str ();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 bool Duration::operator< (const Duration& other)
 {