Code Cleanup

- The "next" command had two control paths.  One was via custom reports
  (correct) and the other was a residual handler (obsolete), which is
  now removed.  This also simplifies a handleCustomReport/runCustomReport
  issue.

src/main.h

@@ -99,7 +99,6 @@ int shortUsage (std::string &);
 int longUsage (std::string &);
 int handleInfo (std::string &);
 int handleReportSummary (std::string &);
-int handleReportNext (std::string &);
 int handleReportHistoryMonthly (std::string &);
 int handleReportHistoryAnnual (std::string &);
 int handleReportGHistoryMonthly (std::string &);