Persistent does not set totalCount

[kitsonk]

While likely related to #40, this is a separate issue in that Persistent (and I assume Memory and ReadOnly) do not set the results.totalCount. It always returns as undefined.

For example, the following code, you would expect totalCount to be set:

var store = require("perstore/stores").DefaultStore({
  path: "data",
  filename: "example.json"
});

var results = store.query("limit(1,0)", {});

console.log(results.totalCount);

[kriszyp]

The totalCount is only computed if the third argument is supplied:
limit(0,10,Infinity)