Removed IP addresses from comments and from most other listing pages.
IPs take up a lot of space in many places (especially IPv6 addresses),
and in most of these pages they're rarely useful for catching
sockpuppets.
Change calling convention to explicitly indicate whether the attributes
are for the <th> element or the <td> element. Fixes various cases where
the two were mixed up.
* Fix .col-expand classes not being set correctly on the /post_versions,
/pool_versions, and /notes pages.
* Fix .updater and .updated-at classes not being set correctly on the
/forum_topics page.
* Fix the name param being ignored (noticeable in the post count field
on the /tags page).
* Don't pass empty string when column has no name.
* Factor out common sidebar layout template.
* Convert wiki pages and posts to use this template.
* Add data-layout attribute to <body> element indicating the current layout.
Changes to the /wiki_page_versions global listing:
* Add "diff" links that show you what changed in the given edit.
* Add "?" links that take you to the current version of the wiki.
* Add "»" links next to wiki page titles that take you to the wiki's full edit history.
* Add "»" links next to usernames that take you to the user's full edit history.
* Add a "Status" column that shows whether the wiki page was created,
deleted, undeleted, or renamed.
* Link to /wiki_page_versions in sidebar, not /wiki_pages?order=time.
Split the wiki page versions template into two partials,
_global_listing.html.erb and _page_listing.html.erb, to avoid the nested
conditionals that arise from combining these two pages into one template.
Add html IDs to distinguish between these two partials.
It seems that in Danbooru 1 wiki page version's created_at was always
the initial created_at of the wiki page itself, as opposed to the time
that the edit was made like in Danbooru 2.
