Fundraising tech/Paymentswiki upgrade

How to apply a security update

 * fetch the upstream LTS release with e.g. 'git fetch origin REL1_31'
 * If you are on vagrant, you may have to edit your .gitconfig to allow fetching other branches - just deleting the 'fetch' section seems to work
 * look at the changes with git diff origin/REL1_31 or git log -p HEAD..origin/REL1_31
 * get a clean changelog with git log --oneline --reverse --no-merges HEAD..origin/REL1_31 | cat
 * do the merge: git merge origin/REL1_31
 * resolve any conflicts. Note that the fundraising version of the LTS release has images added and has a different set of submodules, so be sure the merge does not delete images or add or delete submodules.
 * test locally!
 * review, merge to fundraising/REL1_31 and deploy.

= Upgrade scenarios =

Schema upgrade required

 * Confirm a recent database backup.
 * Disable campaigns.
 * Disable paymentswiki using LocalSettings variable.
 * 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.
 * Watch logs for 1 hr.

Risky, but code-only changes

 * Disable campaigns.
 * Disable paymentswiki using LocalSettings variable.
 * Update the code to the new release.
 * Reenable paymentswiki and test.
 * Reenable campaigns.
 * Watch logs for 1 hr.

Safe, code-only changes

 * Update the code REL1_31 the new release.
 * Watch logs for 1 hr.