Hide the "Formatting help" link for single-line DText fields in dialog boxes, such as after the
"Reason" field in the flag, appeal, and report dialog boxes.
Adjust input boxes to fit the screen better on mobile, and to use
consistent sizes throughout the site (no ad-hoc overrides to make
certain input boxes a bit bigger in random places).
On desktop, this makes most input boxes a bit taller and narrower. On
mobile, it makes input boxes the full width of the screen.
This most notably affects the tag edit box, the comment and forum
post box, the wiki page edit box, and the commentary box.
Disable the browser's native spellchecking ability on all form inputs,
except for DText inputs. We do this by setting `spellcheck="false"` on
the <body> tag, and `spellcheck="true"` on DText <input> tags.
This fixes browsers displaying a red wavy underline beneath tags in the
tag search box, among other places. We disable spellchecking globally
because most form inputs, except for DText inputs, aren't meant for
natural English language.
* Refactors DText form fields to use a custom SimpleForm input instead
of manually generated html. This fixes it so that DText fields use the
same markup as normal SimpleForm fields, which lets us apply browser
maxlength validations to DText input fields.
* Fixes autocomplete for @-mentions only working in comments and forum posts.
Now @-mention autocomplete works in all DText fields, including dmails.
Known bug: it applies in artist commentary fields when it shouldn't.
