File Editor: Remove background
Merge branch 'master' of https://github.com/StylishThemes/GitHub-Dark

* 'master' of https://github.com/StylishThemes/GitHub-Dark:
  version bump
  Issues: Update line length hack #136
  Wiki: Brighten wiki edit link. See #141
  Wiki: add hover to back arrow. See #141
  Wiki: remove editor background & fix sidebar link colors. See #141