I moved my old wiki directory and created a new directory to test the 1.4 Beta.
I used an existing database. I copied these three lines from my old
LocalSettings.php directory and into the new one created by the install script:
$wgWhitelistAccount = array ( 'user' => 0, 'sysop' => 1, 'developer' => 1 );
$wgWhitelistEdit = true;
$wgWhitelistRead = array ("Special:Userlogin");
The old version of the wiki prevents any non-logged-in user from doing anything
but logging in. The new version does no such thing.