Move html_data_attributes definitions from models to policies. Which
attributes are permitted as data-* attributes is a view level concern
and should be defined on the policy level, not the model level. Models
should be agnostic about how they're used in views.
* Add index on posts.is_deleted. The modqueue was slow because we the
appeal condition wasn't constrained to deleted posts, so it degraded to
a full table scan.
* Avoid extra queries for calculating the page count and disapproval counts.
* Only show the current pending flag on flagged posts. Don't show old flags.
* Don't show both the "This post was flagged for review" and the "This
post was flagged and is pending" notices.
* Only show the current pending appeal in the "This post was appealed"
notice. Don't show old appeals.
* Don't show both the "This post was deleted" and the "This post was
appealed" notice on appealed posts. Only show the "This post was
appealed" notice.
* Show "no reason" if no appeal reason was given.
Fix broken links on various pages:
* The 'History' link in the sidebar on the post index page.
* The 'History' links on the tags index page.
* The 'Tag History' link in the sidebar on the wiki show page.
If a pending post is manually deleted before the 3 day moderation period
is up, then make it cost 5 upload slots until the 3 day period is up.
This means that if a new user uploads 3 bad posts that get manually
deleted, then all of their upload slots will be used and they won't be
able to upload again until 3 days have passed.
* Fix#4552: Multiple quoted search terms not parsed correctly.
* Allow quotes to be escaped in quoted metatags.
* Allow spaces to be escaped in unquoted metatags.
* Allow the empty string to be used in metatags.
Examples:
* `source:""` and `source:''` (same as `source:none`)
* `source:foo\ bar\ baz` (same as `source:"foo bar baz"`)
* `source:"don't say \"lazy\""` (use \" to write a literal ")
* `source:'don\'t say "lazy"'` (use \' to write a literal ')
* `source:"C:\\Windows"` (use \\ to write a literal \)
