sources without package get recompiled each time

I fixed this by adding the directories those files are in as source roots.

Our main source root is:

src/

But we had some package-less classes under:

src/com/mycomp/legacy

So I added src/com/mycomp/legacy as a source root, and that stopped them from making every time.

BTW, I think this is a problem with javac as well. Our ant build was doing the same thing, and we fixed it by excluding those directories from our main task, and adding additional ]]> tasks with the more specific src roots.