ASACORE-1296: AboutListener sample which shows all About annoucements

Create a variant of the AboutClient sample which listens for all About
announcements and prints out the resulting data. This is a useful tool
for testing AllJoyn applications.

Change-Id: I43430c23b89c3840d33b49640fe30523656ce5de
Signed-off-by: Rob Smith (WINDOWS) <robs@microsoft.com>
Merge "ASACORE-1296: AboutListener sample which shows all About annoucements"