integrate "tag_slug__not_in" parameter to wp_query

[alexvorn2]

if there are for ids:

tag__and (array) - use tag ids.

tag__in (array) - use tag ids.

tag__not_in (array) - use tag ids.

and for slugs:

tag_slug__and (array) - use tag slugs.

tag_slug__in (array) - use tag slugs.

then there should be

tag_slug__not_in

too.

We have tax_query for this.