WIP: port a test to use the multi-node framework.
Further WIP-saving.
Add a mechanism for federation to run multiple nodes in one distributed system, and thus port the rest of the mutli-node tests. There is still a great deal of detritus to be removed...
Port all the in-broker tests.
Remove some no-longer-needed stuff
Add needed dependency so we can test from clean.
Easier to just override this than tweak the umbrella.
API change, slight cleanup.
Don't assume paths.
Merge bug26162
stable to default