Add more -webkit pseudo elements to PseudoElement
Add more -webkit pseudo elements to PseudoElement

After a bit of Googling, I found what appears to be a pretty good list
[0] of pseudo elements in WebKit-based and WebKit-like-based (e.g.
Blink) browsers. This commit adds the missing pseudo elements to our
list.

I decided to change from wrapping these to having one per line because
it will make it easier to make modifications and see diffs in the
future. My next commit will convert the other items here to one per line
for consistency.

[0]: http://tjvantoll.com/2013/04/15/list-of-pseudo-elements-to-style-form-controls/

teoljungberg/scss-lint,cih/scss-lint