Merge change 8917 into donut

* changes:
  implement api level toggling  and rename navtree.js to android-developer-reference.js for all reference related scripts  TODO: shading for hidden classes in the treeview navigation... these aren't dynamic yet.
tree: 247f8a535aa21d783d474ff8beaf3cb482427153
  1. core/
  2. libs/
  3. target/
  4. tools/
  5. buildspec.mk.default
  6. cleanspec.mk
  7. envsetup.sh