Updated the previous build testcase and added a few more files to download. I
also updated comments to describe a solution to the problem. Using
SubBuildListener instead of just BuildListener and having subBuildFinished()
call buildFinished(). Ater this change, "vfs_cache" always gets cleaned up no
matter what. One caveat is that it is Ant-1.6.2+ specific, so the current
dependency of Ant-1.5 will have to be updated to Ant-1.6.2 if this solution is
to be feasible. I will be uploading a patch provides the fix to VfsTask.java.
If this is applied, then this bug can be truly marked as Fixed!