In the Installer, some NEXT buttons have different styles (one is a Red link others a button). We should be consistent and use only one style.
Also, a small related feedbakc: in the installation after creating a website, the page shows the green message at the top, and the text then "disappears" and results in the text content to "jump up" the screen. instead the Green text should disappear but not remove Space so that it does not jump.
In 141a2df19957f4ccd07ee3df851e453b4fba5b5f: Retain space after fadeOut by using show() on DOM element.
fadeOut uses display: none always!
Assign nextStep links the .submit class.
fixes #3617