Enabled exclude_from_search for non trivial queries. #661

@himanel1 Please have a look and maybe you can try this somehow. It requires more changes than I like and I hope that I did not create any new bugs. exclude_from_search should not work for all queries. I think, I might also catch a few more issues about the handling of nested documents.

Currently, I have no pre agg filter ... so technically it is (aggs + 1) queries that are run internally. This is still an optimisation that needs to be added. Therefore the draft state.