Changes to handle PDPX deploy/undeploy

Changes to handle PDPX deploy/undeploy

Added changes to handle incoming udpate for deploying or undeploying the
policies by comparing both sets.  STill need to add support for removing
the policies and getting the deployed ToscaPolicyIdentifiers for
PdpStatus response.

* PLD - added functionality to unload policies in the applications and
* PLD - added map of loaded policies

* Mike - made change to address Jim's and Joshua's comments
* Mike - Made change to use mapLoadedPolicies to get deployed policies
from the applications
* Mike - made change to assembly.xml to add support for apps directory.

Change-Id: If7d119197171b68b905b7fd0f2b5be6cf6f609e7
Issue-ID: POLICY-1451
Signed-off-by: Michael Mokry <michael.mokry@att.com>
Signed-off-by: Pamela Dragosh <pdragosh@research.att.com>