Log Message:
Update to 3.20141016. From the changelog:

[ Joey Hess ]
* Fix crash that can occur when only_committed_changes is set and a
  file is deleted from the underlay.

[ Simon McVittie ]
* core: avoid dangerous use of CGI->param in list context, which led
  to a security flaw in Bugzilla; as far as we can tell, ikiwiki
  is not vulnerable to a similar attack, but it's best to be safe
* core: new reverse_proxy option prevents ikiwiki from trying to detect
  how to make self-referential URLs by using the CGI environment variables,
  for instance when it's deployed behind a HTTP reverse proxy
  (Closes: #745759)
* core: the default User-Agent is now "ikiwiki/$version" to work around
  ModSecurity rules assuming that only malware uses libwww-perl
* core: use protocol-relative URLs (e.g. //www.example.com/wiki) so that
  https stays on https and http stays on http, particularly if the
  html5 option is enabled
* core: avoid mixed content when a https cgiurl links to http static pages
  on the same server (the static pages are assumed to be accessible via
  https too)
* core: force the correct top URL in w3mmode
* google plugin: Use search form
* docwiki: replace Paypal and Flattr buttons with text links
* comments: don't record the IP address in the wiki if the user is
  logged in via passwordauth or httpauth
* templates: add ARIA roles to some page elements, if html5 is enabled.
  Thanks, Patrick

pkgsrc changes:
* For the python option, add missing py-expat dependency.