build failed, because of missing directory

Hello,

the basic build script failed, because the ```java/sound``` directory was missing. The reason is, that we migrate the sound library out of the main repository ([3c3fb4f](https://github.com/processing/processing/commit/3c3fb4f1a497b5da6e5a35186a94365f0b2b0727)). I just commented out the paths in the ```build.xml```, because I don't know if it will come back.

Happy coding,
Darius