Feature #934

- Feature #934, supports 'reserved.lines' to indicate a multi-line prompt for
  use in conjunction with 'limit:page' (thanks to Robert Gill).
- Removed 'locale' from the taskrc.5 man page.
- Added verbosity token 'sync'.
- Fixed bug in size calculation for 'limit:page', but there is still one more.
- Corrected unit test limit.t given the above fix.

src/commands/CmdCustom.cpp

@@ -145,9 +145,11 @@ int CmdCustom::execute (std::string& output)
 
   // Adjust for fluff in the output.
   if (maxlines)
-    maxlines -= (context.verbose ("blank") ? 1 : 0)
-              + table_header
-              + 1;  // "X tasks shown ..."
+    maxlines -= table_header
+              + (context.verbose ("blank") ? 1 : 0)
+              + (context.verbose ("footnote") ? context.footnotes.size () : 0)
+              + (context.verbose ("affected") ? 1 : 0)
+              + context.config.getInteger ("reserved.lines");  // For prompt, etc.
 
   // Render.
   std::stringstream out;
@@ -183,6 +185,7 @@ int CmdCustom::execute (std::string& output)
     rc = 1;
   }
 
+  feedback_backlog ();
   context.tdb2.commit ();
   output = out.str ();
   return rc;