Default sort doesn't work with "deep" properties

[ashleahhill]

I'm submitting a ...

[ ] bug report => search github for a similar issue or PR before submitting
[x] feature request
[ ] support request => Please do not submit support request here

Current behavior
When you specify a "deep" property as the prop for a column:

new TableColumn({
    name: 'Cylinders',
    prop: 'engine.cylinders'
}),

or

            <datatable-column name="Cylinders" prop="engine.cylinders">
              <template let-value="value">
                {{value}}
              </template>
            </datatable-column>

Sort malfunctions, the entire data set is not sorted.

Expected behavior
All rows are sorted based on the value for the column. This is the behavior for rows that use a "shallow" property

Reproduction of the problem
http://plnkr.co/edit/9Eug63qi775HVCMe3BhO?p=preview

1. On either the "Expressive: Cars" tab or the "Templated: Cars" tab, try to sort by Formation
2. See that the sort does not work.
3. On either the "Expressive: Cars" tab or the "Templated: Cars" tab, try to sort by Color
4. See the the sort does work

What is the motivation / use case for changing the behavior?
I need to sort on deep properties,

Since its trivial (from the usage standpoint) to display these properties using the prop input, it seems like sorting by them should be supported by the default sort

Please tell us about your environment:
Windows
VSCode
Node
Webpack Dev Server

• Table version: 0.7.x
  0.9.2
• Angular version: 2.0.x
  @angular/core@2.0.1
• Browser:
  Only tried in Chrome
• Language:

TypeScript@2.0.3

[amcdnl]

We probably just need to apply similar code as this does - https://github.com/swimlane/angular2-data-table/blob/master/src/components/body/body-cell.component.ts#L34 ... Can you PR that?

[ashleahhill]

@amcdnl,
Submitted