Changed my mind - it's a good idea to wait a short time before
sending a keepalive request: this will make sure we never
tightloop.
This also adds a 'RECONNECTING' state for when a sync request has
failed but there is no reason to suspect there is actually a
connectivity problem. This is necessary for the tests to be able
to advance the clock at the appropriate time, but could be nice
for clients. Add a breaking change changelog entry since
technically this is an API change that might break clients if they
were relying on 'SYNCING' always coming before 'ERROR' for some
reason.
David Baker
92ae4dda72