Coping with multiple targets

Hi. I'm a newbie to Android and Ant so I don't know whether this fix would be useful generally, but it would certainly have saved me some debugging time. I've been learning Android programming from a book and have been doing

    ant clean debug install

for every build. This failed when I switched to Scala using your Ant script modifications. My fix would tell someone in a similar situation why building failed.

Thanks for having put your modifications on Github. I really appreciate it.