Added an extra condition to make sure that observables are compared correctly within an array. `typeof observable == "function"` returns true for observables, so they are treated like a predicate instead of value. With this check, the observables are compared like values.
Add tests showing proper behavior when removing or "destroying" observables in an observable array.
Exposed the $item variable within a foreach binding. $item refers to the raw, potentially wrapped value, where $data does not.
Don't unwrap observable array items in the foreach binding; instead let the binding context manage it. The result of this change is that if the observable is updated, only the underlying binding are updated (using the new observable view model system) instead of the whole template (re-rendering and re-bindings the elements).

Add tests for this change and the previous $item addition.
Use $rawData in place of $item for referencing an observable view model. $rawData will work for any observable view model, not just for ones in an array.
Remove $dataFn from the binding context because $rawData works fine as a replacement.
Merge pull request #482 from knockout/482-arrays-of-observables

Knockout should better handle arrays of observables