Migrate .page-tags rules from wiki-screen
Remove unused template class from wiki-screen
Migrate #content-fields rules from wiki-screen
Remove section editing rules from wiki-screen

These rules are currently not used, and would most likely need to be
updated anyway.
Remove .wrap, and #content rules from wiki-screen

These classes do not seem to appear anywhere that wiki-screen is used.
Remove unneeded #id_content rule from wiki-screen
Migrate #page-attachments rules from wiki-screen
Migrate .title rules from wiki-screen
Migrate editing rules, update translate page

This commit migrates all .editing rules from wiki screen, creates a new
stylesheet called wiki-edit.styl, and corrects a significant bug in the
design of the translation page.