Enhancements - custom reports

- Converted active, overdue and completed reports to custom reports.
- Added new recurring report.
- Added support for new 'end' column, which is the completion date.

src/main.h

@@ -93,14 +93,11 @@ std::string longUsage ();
 void filterSequence (std::vector<T>&, T&);
 void filter (std::vector<T>&, T&);
 std::string handleInfo ();
-std::string handleCompleted ();
 std::string handleReportSummary ();
 std::string handleReportNext ();
 std::string handleReportHistory ();
 std::string handleReportGHistory ();
 std::string handleReportCalendar ();
-std::string handleReportActive ();
-std::string handleReportOverdue ();
 std::string handleReportStats ();
 std::string handleReportTimesheet ();