some backend work for the remaining missing bits of mod_hubman - this is still a fair ways from being complete and is not ready for prime time. Basically we'll let a channel send out a public message saying "these are my currently approved locations" and anything that isn't in the list will be marked deleted. We'll send out this message when locations change somehow - either through direct personal involvement (hub revoke, change primary, channel import) or during a system rename or "find bad/obsolete hublocs" activity. This way we won't have clones sending back location info we just got rid of and re-importing the bad entries.
Merge https://github.com/friendica/red into pending_merge