* New Negentropy protocol: Syncs with older versions of strfry will break (sorry!)
* Bi-directional frame size limits: fixes a bug when syncing very large DBs where the client side was near empty
* sync command now politely tells server it can release Negentropy resources as soon as reconcile complete
This fixes a rare race condition that caused a segfault on exit:
We call ::exit() which runs the atexit handler, which destroys the LMDB environment. However, there was another thread running that still had pending events to write, so as the environment was being destroyed, it tried to use the environment to write the events.
