neuprint_fetch_custom(cache=T) misses #181
Description
neuprint_get_fields() is a very slow call. Sometimes the cache seems to miss for reasons that I can't quite figure out. I suspect that it's something to do with the conn argument. More particularly the conn$authresponse portion which can be quite complex and perhaps doesn't always hash as expected.
I think it might be useful to give neuprint_fetch a cache option (it doesn't have one at the moment, only neuprint_fetch_custom) and strip off the unnecessary parts of the connection object.