Updating npm post-publish steps

Doing a file-by-file reversion was not working for files housed in submodules (e.g. external/shared).  I changed the work flow to just do a hard reset of the main repo and all submodules.

Be careful when running postpublish.js now!  You could lose staged changes in your repo.
Merge pull request #376 from khawkins/fix_npm_post_publish

Updating npm post-publish steps
Merge remote-tracking branch 'upstream/master' into unstable
Merge pull request #378 from khawkins/unstable

Android SDK: Merging master into unstable