Log Message:
Update to 3.20170110. From the changelog:

[ Amitai Schleier ]
* wrappers: Correctly escape quotes in git_wrapper_background_command

[ Simon McVittie ]
* git: use an explicit function parameter for the directory to work
  in. Previously, we used global state that was not restored correctly
  on catching exceptions, causing an unintended log message
  "cannot chdir to .../ikiwiki-temp-working: No such file or directory"
  with versions >= 3.20161229 when an attempt to revert a change fails
  or is disallowed
* git: don't run "git rev-list ... -- -- ..." which would select the
  wrong commits if a file named literally "--" is present in the
  repository
* check_canchange: log "bad file name whatever", not literal string
  "bad file name %s"
* t/git-cgi.t: fix a race condition that made the test fail
  intermittently
* t/git-cgi.t: be more careful to provide a syntactically valid
  author/committer name and email, hopefully fixing this test on
  ci.debian.net
* templates, comments, passwordauth: use rel=nofollow microformat
  for dynamic URLs
* templates: use rel=nofollow microformat for comment authors
* news: use Debian security tracker instead of MITRE for security
  references. Thanks, anarcat
* Set package format to 3.0 (native)
* d/copyright: re-order to put more specific stanzas later, to get the
  intended interpretation
* d/source/lintian-overrides: override obsolete-url-in-packaging for
  OpenID Selector, which does not seem to have any more current URL
  (and in any case our version is a fork)
* docwiki.setup: exclude TourBusStop from offline documentation.
  It does not make much sense there.
* d/ikiwiki.lintian-overrides: override script-not-executable warnings
* d/ikiwiki.lintian-overrides: silence false positive spelling warning
  for Moin Moin
* d/ikiwiki.doc-base: register the documentation with doc-base
* d/control: set libmagickcore-6.q16-3-extra as preferred
  build-dependency, with virtual package libmagickcore-extra as an
  alternative, to help autopkgtest to do the right thing