* Allocate channels to relays only if they have free space based on
their chanlimit value
* Minify channels by removing ones that are already covered before
passing them off to be joined
* Low-key channel joining with incrementally increasing delay
* Spin up needed instances to be able to cover a certain channel space
* Fix provisioning functions to prevent race conditions with lots of
relays being created at once
* Tweakable switchover from covering all channels to only covering
channels with more users than the mean of the cumulative user count
Mark Veidemanis