make it ready for packaging

I've looked into packaging supysonic for archlinux and whats bothering me is the templates directory.
https://docs.python.org/2/distutils/setupscript.html#installing-package-data states

```
The paths are interpreted as relative to the directory containing the package
(information from the package_dir mapping is used if appropriate)
```

So it must be either
````
package_data={'supysonic': ['../templates/*.html']}
````
or the templates directory must be moved into the package directory, which makes more sense to me.