Feature #415

- Added feature #415, which supports displaying just a single page of tasks,
  by specifying either 'limit:page' to a command, or 'report.xxx.limit:page'
  in a report specification (thanks to T. Charles Yun).
- Modified the 'next' report to only display a page, by default.

src/main.h

@@ -117,6 +117,7 @@ int runCustomReport (const std::string&, const std::string&,
 		     std::string&);
 void validReportColumns (const std::vector <std::string>&);
 void validSortColumns (const std::vector <std::string>&, const std::vector <std::string>&);
+void getLimits (const std::string&, int&, int&);
 
 // rules.cpp
 void initializeColorRules ();