Fundraising tech/Paymentswiki upgrade

The process to upgrade paymentswiki, when a schema change is required, should be something like:
 * Confirm a recent database backup.
 * Disable campaigns and paymentswiki.
 * Update the code to the new release.
 * Enable writability on the master wiki database (payments1001)
 * Login to payments1001, cd to the wiki root directory, and run "php maintenance/update.php".
 * Reenable paymentswiki and test.
 * Reenable campaigns.