merge from open-source master

Change-Id: I9fedeb014c946b53bfdd424b00c0cb5fc08f8333
tree: f2a9ca34e2b784500f4fee9e19c25592a782dd19
  1. core/
  2. libs/
  3. target/
  4. tools/
  5. .gitignore
  6. buildspec.mk.default
  7. envsetup.sh