Default configuration should do something useful, in sandbox mode. Document required and additional configuration. Get rid of the pre/post config trickery. Expect that all DI LocalSettings.php stuff will appear after the DI require line.
For an illustration of the problem,
```
$wgDonationInterfaceEnableGlobalCollect = true;
$wgDonationInterfaceEnableWorldPay = true;
$wgDonationInterfaceEnableFormChooser = true;
$wgContributionTrackingDBserver = 'localhost';
$wgContributionTrackingDBuser = 'user';
$wgContributionTrackingDBpassword = 'pass!23';
$wgContributionTrackingDBname = 'drupal';
require_once "$IP/extensions/ContributionTracking/ContributionTracking.php";
require_once "$IP/extensions/DonationInterface/DonationInterface.php";
require_once 'DonationInterfaceFormSettings.php';
$wgDonationInterfaceUseSyslog = true;
$wgDonationInterfaceFallbackCurrency = 'USD';
$wgPaypalGatewayXclickCountries = array();
$wgPaypalGatewayAccountInfo['default'] = array(
'AccountEmail' => "tech+test@localhost.net",
);
```