Bug: extremely long sources cause the Tags column to become extremely
wide. Caused by the source link not having the word-break property set.
Fix: use post_source_tag, which lets the `a[rel=external] { word-break: break-word; }`
rule take effect.
Example: https://danbooru.donmai.us/post_versions?search%5Bpost_id%5D=3809742
Side effects:
* The data-current-user-is-voter <body> attribute has been removed.
* {{upvote:self}} no longer works. {{upvote:<name>}} should be used instead.
Rework how posts are displayed in the modqueue:
* Rearrange post info to take up less space and to be consistent with
how posts are shown on the comments index.
* Reduce font size of approve / reject options.
* Reduce empty space around thumbnails and between posts.
* Add size info beneath thumbnails.
* Allow voting on posts.
* Use PostPresenter.preview to standardize rendering of thumbnails. This
adds parent/child borders, tooltips, and data attributes.
