ClassFileImporter doesn't import packages, if respective Jar Entry is missing

[codecholeric]

The current implementation relies on ClassLoader#getResources("/some/pkg") to import package some.pkg. This works for most Jars, however, if the Jar doesn't contain an entry for the respective folder, getResources(..) will return an empty array, and thus classes won't be imported.

An easy way to reproduce this, is to import java.io and observe, that java.io.File will be missing. This happens, because the default rt.jar is missing the entry /java/io, but has an entry /java/io/File.class.

Obviously, this is not desired behavior, because the import of packages should not depend on whether or not the respective Jar has folder entries or not.