Close timing loop-hole when YAML updated

Close timing loop-hole when YAML updated

Noticed when YAML updates are pushed close together that some
Params objects are deleted that should not be.  Fixed that by
eliminating the "active" list concept and only deleting a Params
object that has an associated cleaner.  If it has no cleaner,
then it can't be deleted, regardless of timing with rule updates.

Added more tests for rule updates, including cases to check
for event objects being retracted, as well as Params objects
being retracted when rules are deleted.

Change-Id: I6b744b29fca228022f43e9322ea149b16d097675
Issue-ID: POLICY-1248
Signed-off-by: Jim Hahn <jrh3@att.com>