Thin out axis and customize labels

![screen shot 2014-12-16 at 10 32 19 am 2](https://cloud.githubusercontent.com/assets/1977405/5456103/2d4dd1f2-850f-11e4-9b5c-e1e437503ddb.png)

This is a strong anti-pattern, since it is an implicit dependency on a parent scope variable. Rather than this, you should have an additional two-way bound scope property defined that is watched for changes. We can pair on this quickly if that would help.

Same goes for the other vars defined using $scope.$parent.