Update cache key names in HACKING.md
Remove the leftovers of the old merge interface
MBS-6820: document the setup of master servers, and other trivia about running a master for testing replication.
Make it possible to send ISE emails for new-RE ISEs (and perhaps other places, in the future)
Remove reference to unused wizard_session key
Merge remote-tracking branch 'nikki-bitbucket/remove-ancient-stuff' into beta-no-release-editor

* nikki-bitbucket/remove-ancient-stuff:
  Remove the leftovers of the old merge interface
Merge branch 'mbs-6820-replication-docs' into beta-no-release-editor

* mbs-6820-replication-docs:
  MBS-6820: document the setup of master servers, and other trivia about running a master for testing replication.
Merge branch 'beta-no-release-editor' into beta

* beta-no-release-editor:
  MBS-6820: document the setup of master servers, and other trivia about running a master for testing replication.
  Remove the leftovers of the old merge interface
Merge remote-tracking branch 'bitmap/update-cache-keys' into beta

* bitmap/update-cache-keys:
  Remove reference to unused wizard_session key
  Update cache key names in HACKING.md
Merge branch 'new-re-ise-emails' into beta

* new-re-ise-emails:
  Make it possible to send ISE emails for new-RE ISEs (and perhaps other places, in the future)