-use looping call for running manage function rather than a scheduled
callLater
-track announce speed
-retry store requests that failed up to 3 times
-return a dict of {blob_hash: [storing_node_id]} results from
_announce_hashes
_refreshRoutingTable inline cb refactor
-add and use DeferredLockContextManager
-don't trap errback from iterativeFindNode in iterativeAnnounceHaveBlob
It doesn't seem necessary to wait up to 60 seconds for a new blob to
be announced to the dht. Immediately announce it and schedule the next
announce time as usual.
