hidden: remove tags use in hidden computation
Tags initially prevented revision to be hidden. It seemed a bad idea to have
tags refer to revisions that one can't see. But proper filtering of hidden
revisions excludes them from tag computation. Coming changelog filtering will do
that. Anyway, tags that really matter will likely be public and therefore not
hidden.
The current working directory parent and bookmarked revision are still not
hidden. Bookmarks were likely automatically moved at rewrite time, bookmarks
that remain on obsolete revisions were probably moved there on purpose.
Hello, Foobar
['Hello, Fo, =;o', 'Hello, Bar']