* Revert "Drop the Chain watch channel lock before accessing the finalized state"
This reverts commit 8870944d1323fc31e2d009b9938623de6fcbe50f.
* Add a WatchReceiver wrapper that always clones the borrowed watch data
This avoids deadlocks, by holding the read lock for as short a time as possible.
* Drop the shared Arc<Chain>s as quickly as possible
This reduces memory usage.
* Make read::block more flexible, by accepting any AsRef<Chain>
* Make the block method docs consistent
* Avoid livelocks by explicitly dropping the borrow after the clone
teor