Optimizing lists (Admin Panel: Tools->Autover->[Lists])

- add link to file lists (Admin Panel: Tools->Autover->[Lists]);
- add numbering to file lists;
- sort the lists;
- add error message "This plugin is currently not used!" to all plugin pages;
- add option "autover_is_working" to manage the error message above;
- add title attribute to code snippet in IMPORTANT tab (Admin Panel: Tools->Autover->[Lists]).