Merge change 2594 into donut

* changes:
  new image diffing tool and support for image patches in applypatch
tree: 55a8417266e22f04d168c3b0d02d92e8f48eeb42
  1. core/
  2. libs/
  3. target/
  4. tools/
  5. buildspec.mk.default
  6. cleanspec.mk
  7. envsetup.sh