Allow guards to be dynamically enabled/disabled

Allow guards to be dynamically enabled/disabled

Modified drools-apps so that guards can be dynamically enabled and
disabled.  Due to the current design, there are two properties that
control this:
- an actor-level property: when enabled, the DB connection is created,
  otherwise a stub connection is created.  This property is NOT dynamic
- an engine-level property: when enabled, the connection created by the
  actor is used, otherwise a stub connection is used.  This property IS
  dynamic

Issue-ID: POLICY-2748
Change-Id: I2a5baf908ce274f2eb46a6a3f01df1b3532038ff
Signed-off-by: Jim Hahn <jrh3@att.com>