Convert al_* functions to properties using workaround in #3

This compiles, but there is an `EXC_BAD_ACCESS` when calling `relateTo()` in the unit tests:

![screen shot 2014-06-22 at 3 12 36 pm](https://cloud.githubusercontent.com/assets/353158/3352762/5f5cc8aa-fa5a-11e3-9249-8ed579092786.png)

@noahd, any idea what's going on here?