Changes under this ticket will cover the following changes to the $indexStats aggregation source output:

1. Removing namespace (which is redundant)
2. Name changes to several of the output fields to bring in line with server naming convention

The new output format will be as follows:

{
    "name" : "a_1",
    "host" : "foo:27017",
    "accesses" : {
        "ops" : NumberLong(5),
        "since" : ISODate("2015-09-21T14:11:56.095Z")
    }
}