list all git objects (in recency order)
given a find function, a list of hashes, and an optional list of "end" hashes, list all git objects in recency order as a stream.
var list =open =
create a stream that will start emitting data on the next tick.
find is a function that takes a string object id and a
ready node-style (err, data) callback.
endpoints, if present) should be a list of string object ids.