commit 1bff7c0d1bc76b0d8fd0364070b0a41e38390934
Author: Stu Hood <stuhood@gmail.com>
Date:   Fri Sep 4 17:21:49 2015 -0700

    Don't create directory entries in the isolated context jar

    - Creating directory entries in the isolated context jar causes directory entries in classes_by_target... but we don't need directory entries for jars containing classfiles.