Update build environment, add PIE, fixes issue #572, #580

Note minSDK is now 16.  Need JellyBean or higher to run.
See this for explanation and options: https://code.google.com/p/android-developer-preview/issues/detail?id=888
This was just me simplifying the build when I was testing and getting errors.  Forgot to put those back.  I can't test on those so can't provide a statement regarding them and PIE.