Generally seems to cause issues when secure images are in use.
Was added during laravel upgrade but laravel does not use this directly
for its web middleware anyway.
- Updated editor, and other area, styles to look okay in dark mode.
- Used tinyMCE theme generator to create dark mode theme.
- Updated tinymce to latest 4x version.
- Most elements done, but still need to do editors, tables and final
pass.
- Toggled only by quick js check at the moment, checking via css media
query. Need to make into user-preference toggle.
For #1234
