* Hide the "back" buttons on the completion pages, they are potentially confusing...

* Hide the "back" buttons on the completion pages, they are potentially confusing and almost useless.
* Made the links to the wiki on the completion pages open in the same window, not a popup.
* Do not allow the user to regenerate LocalSettings.php when $wgUpgradeKey was given and the DB settings were prefilled, since this allows a leak of $wgUpgradeKey to escalate to a leak of $wgDBpassword. It's not unreasonable to require that the user removes their old LocalSettings.php when they wish to generate a new one.
* Rewrote the doc comment on $wgUpgradeKey, to discourage users from setting it to an easily guessable string, per concerns on CR r78118.