fixes compile errors in famitracker (lib + app) on osx

osx version: 10.9.2
qt version: 4.8.5

There's still a lot of issues with the ui but loading and playing a tune works.
![screenshot of famitracker running on osx](https://cloud.githubusercontent.com/assets/349748/2776623/1f70f5a2-cad7-11e3-953d-c6108aca59de.png)