- Only fire JS equal heights if flexbox is not supported
- Add flexbox styles for backend sections that used to use
JS based equal heights
- Use Modernizr's flexbox detection to use the old styles
as a fallback for non-flexbox browsers
- Generate new oldie stylesheet
- Do not use .clearfix with flexbox (Safari doesn't like it)
- Apply IE11 fix for flexbox, see goo.gl/pglrbm
References #333