ALLJOYN-1980 Add a new tag namespace (and corresponding macros) for AllJoyn services

With the introduction of services viz. Notifications, AboutConfig (and
later on OnBoarding), the services themselves and the application written
on top of these services have to use the same AJ_APP namespace. This
complicates the code (see how this file defines its message ids).

Its better to have:
  1.And AJ_SVC_ID_FLAG tag namespace that the services can use to define
  their own message ids.
   NotificationService, AboutConfig and others could define their own
   sub-spaces in this namespace, if desired.
  2.Add AJ_SVC_MESSAGE_ID macros

   With these in place, services could define their service-specific
   handler method to handle service-related messages (similar to
   AJ_BusHandleBusMessage(&msg);), and apps would have simpler code.
ALLJOYN-2061 DB143 throws nullpointer for negative encryption tests

Currently only PINX authentication is supported. Reject the authentication is the authentication mechanism is unsupported (RSA, etc.)
Fix build break on DB143

a. mutter.c
   should not include stdio.h directly. That is handled by aj_target.h
b. clientlite.c
   PasswordCallback is only used when we have SECURE_INTERFACE
Tighten the unit test

Do not unconditionally test for assertions that depend on
success/failure of previous assertions.