repoview: move changelog.headrevs() override to filteredchangelog Differential Revision: https://phab.mercurial-scm.org/D7241

repoview: move changelog.revs() override to filteredchangelog Differential Revision: https://phab.mercurial-scm.org/D7240

repoview: move changelog.__iter__() override to filteredchangelog Differential Revision: https://phab.mercurial-scm.org/D7239

repoview: move changelog.__contains__() override to filteredchangelog Differential Revision: https://phab.mercurial-scm.org/D7238

repoview: move changelog.tiprev() override to filteredchangelog Differential Revision: https://phab.mercurial-scm.org/D7237

repoview: wrap changelog class when filtering The class doesn't yet do anything. I'll move the filter-aware overrides from the changelog class over one by one to this class in coming patches. That will leave the changelog class simpler and will centralize more of the filtering logic to repoview. I could not measure any performance difference. Differential Revision: https://phab.mercurial-scm.org/D7236

repoview: extract a function for wrapping changelog I would like to clean up the changelog class by moving out knowledge of filtering. The filtering will instead be done in a class that wraps the changelog. This patch prepares for that. Differential Revision: https://phab.mercurial-scm.org/D7235

revlog: move tiprev() from changelog up to revlog This makes the changelog override simpler and it seems more consistent. Differential Revision: https://phab.mercurial-scm.org/D7250