GPLv3 Headers

As an extension of PDroid (licensed under GNU GPLv3) these fall under the GPL
license. This is to affirm that fact and preserve attribution before too many
copies are let loose.

Change-Id: I254cfa62bb33959a56b1f72d7648b5bf3b97cf29
First implementation of updates to support PrivacyServiceException
Modify additional PDroid code to use 'default deny' approach.
Added logging for when privacy service is 'missing', or PrivacyServiceExceptions occur.
Minor code tidy-up.