Update to 3.20150610. From the changelog:

[ Joey Hess ]
* New emailauth plugin lets users log in, without any registration,
  by simply clicking on a link in an email.
* Re-remove google from openid selector; their openid provider is
  gone for good.
* Make the openid selector display "Password" instead of "Other"
  when appropriate, so users are more likely to click on it when
  they don't have an openid.
* Converted openid-selector into a more generic loginselector helper
  plugin.
* passwordauth: Don't allow registering accounts that look like openids.
* Make cgiurl output deterministic, not hash order. Closes: #785738
  Thanks, Daniel Kahn Gillmor

[ Simon McVittie ]
* Do not enable emailauth by default, to avoid surprises on httpauth-only
  sites. Enable it by default in openid instead, since it is essentially
  a replacement for OpenIDs.
* Make the attachment plugin work with CGI.pm 4.x (Closes: #786586;
  workaround for #786587 in libcgi-pm-perl)
* Add a public-domain email icon from tango-icon-theme
* Populate pagectime from either mtime or inode change time,
  whichever is older, again for more reproducible builds
* debian: build the docwiki with LC_ALL=C.UTF-8 and TZ=UTC
* debian/copyright: consolidate permissive licenses
* debian/copyright: turn comments on provenance into Comment
* brokenlinks: sort the pages that link to the missing page, for
  better reproducibility
* Add [[!meta date]] to news items and tips, since the git checkout
  and build process can leave the checkout date in the tarball
  release, leading to unstable sorting
* Sort backlinks deterministically, by falling back to sorting by href
  if the link text is identical
* Add a $config{deterministic} option and use it for the docwiki
* haiku: if deterministic build is requested, return a hard-coded haiku
* polygen: if deterministic build is requested, use a well-known random seed


(schmonz)