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)

created secondary button style, added a couple of variables, played with the plugins page to get the underline in place. Worth a look, but check that I was building everything properly :)

added angular gradient to page and login. Tweaked header underline to not be so heavy. Tweaked stacked logo on login. Created an alternative to avatar when there's no connection to gravatar - could use work, but I think you get the idea.

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