Remove unused, commented out CSS.

See #4102
Fix leave modal when leaving new post

no ref
- set titleScratch to empty string if unset
Merge pull request #4129 from halfdan/fix-leave-modal

Fix leave modal when leaving new post
Fix post settings menu cog alignment and colours
SERP style updates
Fix padding on content preview mobile views
Minor start on CSS Style cleanup

See #4107
Mobile bug fixes for users view
Fix overly tiny text
Fix broken link, remove old html files
Remove about page header on desktop

See #4116
Merge pull request #4118 from JohnONolan/053-fixes
Disable horizontal scrolling in right outlet

Closes #4131

- Adds `overflow-x: hidden;` to `.right-outlet`
Merge pull request #4136 from PaulAdamDavis/fix-right-outlet

Disable horizontal scrolling in right outlet