Drop edited_on modification (move to client code)
Update .gitignore
Further refactor `ModelView`

Rename:
    do_create -> _create
    do_save, before_create, after_create -> do_create
    do_save, before_edit, after_edit -> do_edit

Add:
    do_filter
    do_sort
    do_delete
Move `dashify` to utils. Add `Paginator` to the same
Export `Paginator`