Implement Lazy interface

[cowboyd]

Instead of:

for (var i = 0; i < state.records.length; i++) {
  console.log(state.records[i]);
}

we let you look up the record directly off of the state:

for (var i = 0; i < state.length; i++) {
  console.log(state.get(i));
}

That way we can be lazy about materializing the record array instead of doing it every time. state.records then goes away

[flexyford]

How do we handle getting the length of records ie state.records.length

We have state.totalSize which has never been implemented

[cowboyd]

put the length property right on state. This is the only eager calculation.

[cowboyd]

state.records will cease to exist.

[cowboyd]

Ticket description was updated to reflect using state.length instead of state.records.length

[flexyford]

@cowboyd can i get a review on #10 please