Organize files in tree nicer

[jvoll]

When you add classes in Xcode it isn't exactly clear where they will actually live in the tree. Also, when you move file around in Xcode it just changes how they are organized in the tree in Xcode but not in the actual file system.

As a result of this, the tree seems disorganized even though the project actually looks quite nice. This should be fixed...although it might be a slight pain in the ass. For now, I'll let Xcode abstract this problem away so I don't have to worry about it :)