Rewrote the ws_docfilter() the routine that ensures that an index does not return results from a document that got deleted (as document deletion is largely a no-op, the index structures get polluted with deleted items).
Rewrote the ws_docfilter() the routine that ensures that an index does
not return results from a document that got deleted (as document deletion
is largely a no-op, the index structures get polluted with deleted items).

Before the rewrite, ancestor-or-self was used on the entire candidate list
just to get the document root (typically 1 one very few). Now a more
adaptive approach is taken that uses much less ancestor effort.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb