Merge change 7479 into donut

* changes:
  handle identical gzip chunks better
tree: 0e5a52834071318bcf3546fc1842e1051d3e82f6
  1. core/
  2. libs/
  3. target/
  4. tools/
  5. buildspec.mk.default
  6. cleanspec.mk
  7. envsetup.sh