Update forms.css

Update based on the solution proposed in issue #90.
Update HISTORY.md

Added explanation for commit 297c5ba that fix issue #90
s/following/subsequent
Update with typo for .pure-u-1-6 from 16.656 to 16.666
Update HISTORY.md

Added history for commit 371ce08
Merge pull request #115 from chilts/patch-1

Update with typo for .pure-u-1-6 from 16.656 to 16.666