changectx: use unfiltered changelog to walk ancestors in annotate
Since we are only walking ancestors, it is safe to use an unfiltered repository.
(Because if the original rev is not filtered, none of its ancestors will be).
Differential Revision: https://phab.mercurial-scm.org/D7501
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.