Enhancement - #307 show command

- introduced new show command to display configuration settings
- config command is used to just set config values
- modified documentation
- modified some unit tests calling 'task config' to 'task show'

src/Context.cpp

@@ -210,6 +210,7 @@ int Context::dispatch (std::string &out)
   else if (cmd.command == "colors")           { rc = handleColor                 (out); }
   else if (cmd.command == "version")          { rc = handleVersion               (out); }
   else if (cmd.command == "config")           { rc = handleConfig                (out); }
+  else if (cmd.command == "show")             { rc = handleShow                  (out); }
   else if (cmd.command == "help")             { rc = longUsage                   (out); }
   else if (cmd.command == "stats")            { rc = handleReportStats           (out); }
   else if (cmd.command == "info")             { rc = handleInfo                  (out); }