Twenty Fourteen: remove Accent Color feature. Props celloexpressions, fixes #26220.

git-svn-id: https://develop.svn.wordpress.org/trunk@26567 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fourteen: remove `custom-colors` tag. See #26220.

git-svn-id: https://develop.svn.wordpress.org/trunk@26568 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fourteen: add `min-height` rule to the WP toolbar to ensure that no gap appears in pre-3.8 versions. Props celloexpressions, fixes #25906.

git-svn-id: https://develop.svn.wordpress.org/trunk@26569 602fd350-edb4-49c9-b593-d223f7449a82