* Fix frac lline
For frac-line, use an SVG line in an extra tall span.
I still need to think of a way to adust `vertical-separator`.
* Fix spaces in katex.less
* regenerate screenshots
* update HorizontalBraces and StrikeThrough screenshots
* Change frac-line from border to full span
Change `frac-line` and `vertical-separator`. Instead of using span borders, fill entire span using a `box-shadow`.
This change will enable more dependable engagement of the `min-height` CSS.
* Fix indentation
* Fix indent again
* Change box shadow to inline SVG
* Fix lint error
* regenerate screenshots after switching to SVG for fraction bars
Summary:
This only supports em and ex units and doesn't handle vertical layouts.
Negative kerning works.
Test Plan:
- make test
- make screenshots (verify that d is slightly overlapping c in the screenshots)
Reviewers: emily
