log: add bookmark option to "hg log"
Before pushing a bookmark with "hg push origin -B 'my-topic'", it is useful to inspect
the list of commits that are ancestors of the bookmark.
By relying on scmutil.bookmarkrevs(), "hg log -B topic" has the same bookmark semantics
found in other commands like hg export, hg email, hg strip.
Differential Revision: https://phab.mercurial-scm.org/D9341
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}