Changes

* In rare cases, the user will be manually looking for a given host name or other attribute that occurs in the source but not the destination. This attribute may not appear in the result set.

When queries for visited web pages are done, it is less clear what to do. Since redirects can change temporally, it may not be clear which redirect to use, and which pages deserve to be in the result. The ideal solution depends on what the expected use of non-visit-based history queries are, which is not yet clear. One solution is to not coalesce redirects at all. The other solution is, for a page X, if there is some (or perhaps, the most recent visit) that is a redirect to Y, substitute X with Y. This will be wrong if X's redirect changes, but this should handle most cases.