Fix bug in `siblings`

Do not consider siblings' contents when filtering
Fix bug in `prevAll`

Do not consider siblings' contents when filtering.
Implement `selector` argument of `prev` method
Fix bug in `prevUntil`

Do not consider siblings' contents when filtering.
Implement `selector` argument of `next` method
Fix bug in `nextAll`

Do not consider siblings' contents when filtering.
Fix bug in `nextUntil`

Do not consider siblings' contents when filtering.