Binding ignores object keys that begin with '$'

[uriva]

Codepen:
http://codepen.io/uriva/pen/mVoQZg

[Narretz]

1. leading $ and $$ are public / private API indicators and you should not use them in your objects for that reason
2. The codepen doesn't show the problem
3. The pen is using a very old version of angular - it shouldn't matter in this case, but please always test with the latest stable.

[uriva]

Fixed codepen.

[uriva]

Related to #1463

[Narretz]

Duplicate of #6266 Atm, we don't have plans to fix this and I've recently updated the repeat docs to reflect this.