ux(): tweaks and polish, and also simpifying width classes, gf-size-xxx and gf-size-max-xx are now width-(1-30), and max-width-(1-30)

closes #4064

Fixed bug that wasn't showing the StaticRootPath when validation failed

ux(): began long on tiresome work on color refactors, polished button styles, added buttons to styleguide

Thank you https://github.com/aruetten for helping
us find the new metrics

closes #4053

Arranged http_api docs in a better way

ux(sass): a lot of polish on headings and margins, ONLY USE bottom margins, othewise margin collapse causes issues

closes #4018

In firefox the scrollbar is always show when setting
overflow: scroll. This commit makes sure the overflow
setting is only applied when needed.

closes #4049

Added Confirmation modal for user deletion

Merge branch 'style-changes-bulletfactory' of github.com:grafana/grafana into style-changes-bulletfactory