Add command subcommands: list and exec

Also handle list result

src/ui/ui.h

@@ -377,6 +377,8 @@ void win_show_info(ProfWin *window, PContact contact);
 void win_clear(ProfWin *window);
 char* win_get_tab_identifier(ProfWin *window);
 char* win_to_string(ProfWin *window);
+void win_command_list_error(ProfWin *window, const char *const error);
+void win_handle_command_list(ProfWin *window, GSList *cmds);
 
 // desktop notifications
 void notifier_initialise(void);